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
  • C10L1/18—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

Definitions

• pour point problems arise through the formation of solid or semi-solid waxy particles in the fuel oil, e.g., distillate fuel oils, such as heating oils, diesel oils, turbo-jet fuels and the like, when such fuel oils are subjected to low temperatures in storage.
• a related problem also exists in respect of hydrocarbon resid fuel oils and waxy crude oils, in which the waxy components of such oils adversely affect the flowability and/or pumpability of the oil under low temperature conditions.
• U.S. 3,447,915 issued to B. Otto, June 3, 1969, teaches the use of terpolymers of ethylene, propylene and an alkyl ester of acrylic acid or methacrylic acid as pour point depressors in fuel oils.
• the pour point depressants and flow improvers disclosed in U.S. 3,467,597, issued to N. Tunkel et al., Sept. 16, 1969, are terpolymers of ethylene, vinyl esters, e.g. vinyl acetate, and a monoolefinically unsaturated polymerizable compound grafted with ethylene.
• U.S. Pat. 3,679,380 issued July 25, 1972 to C.
• Biswell et al. discloses middle distillate fuel compositions containing a copolymer of ethylene, propylene and 1,4-hexadiene as pour point depressants.
• U.S. Pat. 3,675,671 issued July 11, 1972 to W. Sweeny et al. discloses such crude oils with a low pour crude oil and a copolymer of ethylene and a vinyl fatty acid ester, such as vinyl acetate.
• additives for fuel oils and crude oils which are effective in lowering the pour point and in improving the flowability and/ or pumpability of such oils at low temperatures, i.e., at temperatures at or below which the waxy components thereof start to become semi-solid or solid, are obtained by hydrolyzing copolymers of ethylene and a vinyl ester of an alkyl fatty acid having up to about five carbon atoms, which copolymers have an average molecular Weight of from about 500 to about 30,000, preferably from about 700 to about 10,000, and contain from about 10% to about preferably from about 25% to about 40% vinyl ester units.
• the hydrolysis of such copolymers is conducted under conditions which will effect the hydrolysis of from about 10% to about 90%, preferably from about 40% to about 70% of the vinyl ester units of the copolymer.
• copolymer Methods of preparing the starting copolymer of ethylene and the vinyl ester, e.g., the vinyl acetate, are well known in the art. Such copolymers can be produced by the copolymerization of ethylene with the vinyl ester under pressure at elevated temperatures, i.e. from about 280 F. to about 350 F. in the presence of a free radical catalyst, such as a peroxy compound. Processes for the preparation of such copolymers are described in US. Pats. 2,396,785 and 3,048,479.
• ethylene vinyl acetate polymers are prepared in a benzene solution using di-tertiary-butylperoxide, as the catalyst, at a temperature of 280-340 F and at a pressure of 7002,000 pounds.
• the vinyl acetate, solvent and catalyst are introduced into the reactor, the sufficient ethylene charged to the reactor to yield the desired pressure at the reaction temperature. Additional ethylene is added during the polymerization to maintain the desired pressure in the reactor.
• the polymerization is considered complete, when a pressure drop of less than 50 p.s.i.g. per hour is observed, The product is then stripped free under vacuum of solids and unreacted vinyl acetate.
• copolymers may be hydrolyzed by alcoholysis or by saponification.
• alcoholysis or by saponification.
• saponification Such methods are well known in the art, as exemplified by U.S. lPats. Nos. 3,344,129; 3,386,978; 3,560,318; 3,560,461; 3,562,234 and others.
• Illustrative of a method of hydrolyzing the ethylene-vinyl ester copolymer is the following: The hydrolysis of the copolymer is carried out under anhydrous conditions by heating the copolymer, preferably diluted to about 2060%, in an inert diluent or solvent, such as for example, kerosene, naphtha, etc., or an aromatic hydrocarbon solvent, e.g. toluene, to reflux temperature while purging with dry nitrogen or other inert gas, then cooling down to a temperature of from about 120 C. to about 50 C., preferably 70 C., while continuing blowing with the inert gas, such as nitrogen.
• an inert diluent or solvent such as for example, kerosene, naphtha, etc.
• an aromatic hydrocarbon solvent e.g. toluene
• the reaction is quenched by adding to the reactor from about 0.005 to about 0.1 mole of the lower alkyl fatty acid corresponding to the vinyl ester, e.g. acetic acid when the vinyl ester is vinyl acetate, and the reaction mass stirred for about 5-10 minutes.
• the quenched reaction mixture is then heated to a temperature of about 120 C.150 C. to strip off volatiles, such as alkanol, alkyl ester of the lower fatty acid, and diluent or solvent light ends.
• the hydrolyzed copolymers of the present invention are effective in petroleum distillate and residual fuel oils, and in petroleum crude oils.
• the fuel oil such as for example, heavy industrial residual fuels, e.g. Bunker C fuel, and crude oils.
• the fuel oil may be virgin or cracked petroleum stock, or mixtures thereof, boiling in the range of from about 200 F. to about 750 F., and preferably in the range of about 350 F. to 750 F.
• the fuel oil may contain other additives such as, for example, rust inhibitors, corrosion inhibitors, antitoxidants, detergents etc.
• the additives of the present invention are used in the fuel oils and crude oils in amounts of from about 0.001% to about 5%, preferably from about 0.0025% to about 1.0%.
• the additives may for convenience, be prepared as addition agent concentrates. Accordingly, the hydrolyzed copolymer may be dissolved in a suitable organic solvent therefor in amounts greater than 5% and preferably about 2575%.
• the solvent in such concentrate preferably has a distillation range of from about F. to about 700 F.
• the organic solvents are hydrocarbon solvents, for example, petroleum fractions such as naphtha, kerosene, heater oil, and the like; aromatic hydrocarbons such as benzene, xylene, and toluene, or paraffinic hydrocarbons such as hexane, pentane, etc.
• the solvents employed should, of course, be selected with regard to possible beneficial or adverse effects it may have on the final fuel oil composition. Thus, the solvent used should preferably burn without leaving an objectionable residue, and should be noncorrosive with regard to metals.
• the ethylene-vinyl acetate copolymer hydrolyzed by alcoholysis or by saponification was a copolymer having an average molecular weight of about 2,400, and containing about 32% vinyl acetate units.
• EXAMPLE 1 Ethanol-Sodium Ethoxide Method 3,180 grams of 52% ethylene-vinyl acetate copolymer solution in kerosene was heated to C. and purged with nitrogen. The solution was then cooled to 78 C., nitrogen purging discontinued, and the cooled solution treated with 1,600 grams of absolute ethanol. The reaction mixture was heated to reflux temperature, ml. of a 1.0 N. sodium ethoxide in ethanol added and the reaction mixture maintained at reflux temperature for one hour. The reaction mass was then quenched with 10 ml. of glacial acetic acid, and the mixture then stripped to 120 C.
• the recovered product as 61% hydrolyzed that is 61% of the ester units of the ethylene-vinyl acetate copolymer were hydrolyzed.
• the degree of hydrolysis was measured by gas chromatography (GC), which measures the amount of ethyl acetate formed as byproduct.
• EXAMPLE III Methanol-Sodium Methoxide Method 100 grams of a 52% ethylene-vinyl acetate copolymer solution in kerosene was heated to 120 C. in a pressure reactor flask while purging with nitrogen to remove any moisture. The solution was then cooled to 60 0., treated with 10 grams of methanol and heated to 100 C.; the pressure in the reactor reaching about 45 p.s.i. 7.5 ml. of sodium methoxide (1 N) was injected into the reaction mixture, and the mixture maintained at 100 C. for one hour. The reaction was then quenched with 2 ml. of glacial acetic acid, cooled to room temperature, the pressure-released, and the volatiles stripped off by heating to 120 C. The recovered product was 80% hydrolyzed.
• Saponification Method 300 grams of a 60% ethylene-vinyl acetate copolymer solution in kerosene was heated to 100 C.
• the solution was then treated with 11 grams of sodium hydroxide dissolved in 30 ml. water, and the mixture maintained at reflux temperature (108-110 C.) for three hours.
• the heated reaction mixture was then treated with 8 'ml. 12 N HCl.
• the resultant acidic solution was heated to 150 C. to distill off the water present in the product.
• the recovered product was 38% hydrolyzed.
• EXAMPLE V Ethanol-Sodium Hydroxide Method 500 grams of a 60% ethylene-vinyl acetate copolymer solution in kerosene and 50 grams of ethanol were heated to reflux temperature. To the refluxing solution was added 50 ml. of 1 N NaOH and the mixture maintained at reflux temperature for four hours. The solution was then treated with ml. of 12 N HCl, and stripped of volatiles at 150 C. The removed product was 11% hydrolyzed.
• Petroleum crude oil and fuel oil compositions having improved pour and flowability characteristics at low temperatures, comprising a petroleum oil of the group consisting of a crude oil and a fuel oil normally having undesirable pour and flowability characteristics at low temperatures, and from about 0.001% to about 5% of a hydrolyzed copolymer of ethylene and a vinyl ester of a lower alkyl fatty acid having up to about five carbon atoms, said copolymer having an average molecular weight of from about 500 to about 30,000, and containing about 1090% ethylene and about l0% of said vinyl ester, said copolymer being hydrolyzed to the extent of hydrolyzing from about 10% to about 90% of the ester units of said copolymer.
• a petroleum fuel oil composition having improved pour and flowability characteristics, at low temperatures comprising a major proportion of a petroleum fuel oil normally having undesirable pour and flowability characteristics at low temperatures and from about 0.0025 to about 1.0% of a hydrolyzed copolymer of ethylene and vinyl acetate, said copolymer having an average molecular weight of from about 700 to about 10,000, and containing about 6075% ethylene and about 40-25% vinyl acetate, said copolymer being hydrolyzed to the extent of hydrolyzing from about 30% to about 70% of the acetate units of said copolymer.
• a petroleum crude oil composition comprising a major proportion of a waxy petroleum crude oil normally having undesirable flowability characteristics at low temperature, and from about 0.0025% to about 1.0% of a hydrolyzed copolymer of ethylene and vinyl acetate, said copolymer having an average molecular weight of from about 700 to about 10,000, and containing about 6075% ethylene and about 4025% vinyl acetate, said copolymer being hydrolyzed to the extent of hydrolyzing from about 30 %to about 70% of the acetate units of said copolymer.
• 4462 about 0.001% to about 5% of said hydrolyzed co- 3,776,247 3 C f r 'et a1. 4462 1 v 1 p0 ymer References Cited 5 PATRICK P. GARVIN, Primary Examiner i UNITED STATES PATENTS Y. H. SMITH, Assistant Examiner 3,344,129 9/1967 Bestian et a1 260-873 CL "fwd 3,386,978 6/1968 Salyer 26087.3 44 70

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Liquid Carbonaceous Fuels (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 1973
  • 1973-03-21 US US00343286A patent/US3846092A/en not_active Expired - Lifetime
• 1974
  • 1974-02-26 NL NL7402581A patent/NL7402581A/xx unknown
  • 1974-03-05 IT IT49045/74A patent/IT1004353B/it active
  • 1974-03-14 FR FR7408711A patent/FR2222426B1/fr not_active Expired
  • 1974-03-20 BE BE142243A patent/BE812589A/fr unknown
  • 1974-03-20 JP JP49032209A patent/JPS49128906A/ja active Pending
  • 1974-03-20 DE DE2413434A patent/DE2413434A1/de active Pending
  • 1974-03-20 SE SE7403785A patent/SE7403785L/ not_active Application Discontinuation

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