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
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/143—Organic compounds mixtures of organic macromolecular compounds with organic non-macromolecular compounds
• • 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
  • 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
  • C10L1/1641—Hydrocarbons macromolecular compounds homo- or copolymers obtained by reactions only involving carbon-to carbon unsaturated bonds from compounds containing aliphatic 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 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
  • 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 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
  • C10L1/16—Hydrocarbons
  • C10L1/1691—Hydrocarbons petroleum waxes, mineral waxes; paraffines; alkylation products; Friedel-Crafts condensation products; petroleum resins; modified waxes (oxidised)
• • 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
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/192—Macromolecular compounds
  • C10L1/195—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C10L1/1955—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by an alcohol, ether, aldehyde, ketonic, ketal, acetal radical
• • 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
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/192—Macromolecular compounds
  • C10L1/195—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C10L1/196—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and a carboxyl group or salts, anhydrides or esters thereof homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by a carboxyl radical or of salts, anhydrides or esters thereof
  • C10L1/1963—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and a carboxyl group or salts, anhydrides or esters thereof homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by a carboxyl radical or of salts, anhydrides or esters thereof mono-carboxylic
• • 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
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/192—Macromolecular compounds
  • C10L1/195—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C10L1/196—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and a carboxyl group or salts, anhydrides or esters thereof homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by a carboxyl radical or of salts, anhydrides or esters thereof
  • C10L1/1966—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and a carboxyl group or salts, anhydrides or esters thereof homo- or copolymers of compounds having one or more unsaturated aliphatic radicals each having one carbon bond to carbon double bond, and at least one being terminated by a carboxyl radical or of salts, anhydrides or esters thereof poly-carboxylic
• • 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
  • 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
• • 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
  • C10L1/22—Organic compounds containing nitrogen
  • C10L1/234—Macromolecular compounds
  • C10L1/236—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derivatives thereof
  • C10L1/2368—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derivatives thereof homo- or copolymers derived from unsaturated compounds containing heterocyclic compounds containing nitrogen in the ring

Definitions

• Dimmick ABSTRACT The response of a middle distillate petroleum fuel oil to the addition of a flow improver, such as a copolymer of ethylene, whereby flow and pumpability at low temperatures are improved, is increased by incorporating said fuel oil a small proportion of a paraffinic wax in sufficient quantity to furnish from about 0.03 to about 2 weight percent of normal paraffin hydrocarbons whose average molecular weight is within the range of from 300 to 650.
• the paraffinic wax that is added has a molar heat of fusion that is greater than the molar heat of fusion of the first wax that separates from the fuel upon cooling to or below its cloud point.
• the added wax contains normal paraffin hydrocarbons ranging from n-C to at least n-C inclusive FUEL OIL WITH IMPROVED FLOW PROPERTIES FIELD OF THE INVENTION
• a copolymer pour point depressant or flow improver of the type comprising a copolymer of ethylene with another ethylenically unsaturated monomer, such as an unsaturated ester or another olefin, wherein the ethylene fonns a backbone along which there are randomly distributed side chains consisting of hydrocarbon groups or of oxy-substituted hydrocarbon groups of up to 16 carbon atoms.
• Heating oils and other middle distillate petroleum fuels e.g. diesel fuels
• These hydrocarbon waxes are largely normal paraffins.
• This interlocking of the crystals sets up a gel structure which causes the fuel to lose its fluidity.
• the lowest temperature at which the oil will still flow is generally known as the pour point.
• the cloud point which is the point at which the oil becomes cloudy because of wax crystallization.
• the cloud point is not affected by the flow improver.
• Small-size crystals are desirable so that the precipitated wax will not clog the fine-mesh screens that are provided in fuel transportation, storage, and dispensing equipment.
• Pour point depressants that function by changing the wax crystals-to a more advantageous-size and shape can thus also be referredto as flow improvers. It is desirable to obtain not only fuel oils with low pour points but also fuel oils that will form small wax crystals so that the clogging of filters will not impair the flow of the fuel-at low operating temperatures.
• a middle distillate petroleum fuel oil blend to a flow improver, particularly of the type comprising a copolymer of ethylene and another unsaturated monomer
• a minor amount of a parafiin wax sufficient to impart to the fuel oil from 0.03 to 2 weight percent, and preferably from 0.1 to 2 weight percent, of normal paraffin hydrocarbons whose average molecular weight is within the range of from 300 to 650.
• the wax that is added is further characterized by having a heat of fusion that is greater than the heat of fusion of the first wax that separates from the untreated fuel when it is cooled to or below its cloud point.
• the heat of fusion of the wax will be in the range of about 15,000 to 42,000 calories per ,mole.
• the heat of fusion of the wax will be'from 3,000 to 1 1,000 calories per mole greater than the heat of fusion of the first wax to'precipitate on cooling from the fuel before the fuel has been treated.
• the paraflin wax that is used for modifying a middle distillate fuel oil in accordance with theinvention can consist of normal paraffins ranging from as low as C l-I up to an average of about C li with individual n-paraffins in the mixture ranging as high as 50 to 60 carbon atoms.
• the number averagemolecular weight'of the wax should be in the range of about 350 to 450. While it is possible to use individual parafi'in hydrocarbons in practicing the invention,
• wax mixtures for distillate fuel oils having final boiling points in the range of 620 to 670 F are those that have normal paraffin hydrocarbons in the range of C to C inclusive.
• the waxes that are added include both well defined waxes and crude waxes, such as slack wax and slop wax, as well as any of the various refinery streams wherein wax is a-predominant constituent.
• the waxes that are used have a heat of fusion of from 40 to 55 calories per gram, and are thus distinguished from petroleum resins, asphaltenes,
• a parafiin wax can be added that contains C and higher'n-parafiingwith the average in the range of C to C While it would be possible for the refiner to introduce higher normal parafiins into the fuel oil simply by increasing the final boiling point of some of the fuel oil components, this would have the disadvantage of making the fuel oil color-unsuch a procedure would have a further disadvantage in that there would be no control over the amount of higher molecular weight waxesthat would be introduced and the desired improvement in low-temperature response would not be obtained.
• the paraffin wax that is used in the practice of this invention is selected on the basis of the thermodynamic properties of the -wax which separates from the fuel to be treated. The choice depends upon'a relation between the enthalphy and entropy of fusion of the precipitating wax and the n-paraffinic wax or wax'mixture that is to be-used. It is possible to characterize the fuel by the following method.
• M (the molecular weight of the fuel) can be measured by ebulirnetric, cryoscopic or osmometric methods. M can also be estimated from distillation data by the formula: Mq T+F 200) 4, where T is the distillation temperature at 10 percent over and F is the distillation temperature at 50 percent over in F. For practical purposes M may be assumed to be about 200 for No. 2 middle distillate fuels.
• the factor 1.03 corrects for the difference in molecular weights of the waxes of interest in this invention and suitable solvents such as naphtha or iso-octane.
• Very crude waxes and waxy materials which contain appreciable amounts (even more than 50 percent) non-n-paraffins may also be characterized by this method.
• the wax to be added is selected so that it will have a heat of fusion which is greater than that'of the first wax which separates from the fuel, with a value of 42,000 calories per mole as the upper limit.
• the wax has a heat of fusion which is 3,000 to 11,000 calories greater than that of the wax which precipitates from the fuel at the cloud point. In some instances optimum results can be obtained with a blend of two or more wax fractions.
• the distillate fuel oil can comprise straight run or virgin stocks, or thermally and/or catalytically cracked petroleum fractions or a blend in any proportion of straight run and cracked distillates.
• the most common petroleum middle distillate fuels are kerosene, diesel fuels, jet fuels and heating oils. They are more fully described in such specifications as MlL-F-25558B (USAF) for turbo jet fuels, ASTM D-396-67 for fuel oils and ASTM D-97567 for diesel fuel oils. Since jet fuels are normally refined to very low pour points there will be generally no need to apply the present invention to such fuels.
• the lowtemperature flow problem is most usually encountered with diesel fuels and heating oil.
• the specifications for a representative No. 2 heating oil include a 10 percent ASTM distillation point no higher than about 440 F., and a 50 percent distillation point no higher than about 520 F., and a 10 percent boiltng point of at least 540' F. and no higher than about 640 to 650 F
• Heating oils are preferably made of a blend of virgin distillate, e.g. gas oil, naphtha, etc., and cracked distillates, e.g. catalytic cycle stock.
• the second unsaturated monomer can be another monoolefin, e.g. a C, to C alpha-monoolefin or it can be an unsaturated ester, as for example vinyl acetate, vinyl butyrate, vinyl propionate, lauryl methacrylate, ethyl acrylate or the like. (See Canadian Pat. Nos. 676,875 and 695,679). Other monomers include N-vinyl pyrrolidone (See Canadian Pat. No. 658,216).
• the second monomer can also be a mixture of an unsaturated mono or diester and a branched or straight chain alpha monoolefin. Mixtures of copolymers can also be used.
• a copolymer pour depressant useful in this invention will consist essentially of about 3 to 40, and preferably 3 to 20, molar proportions of ethylene per molar proportion of the ethylenically unsaturated monomer, which latter monomer can be a single monomer or a mixture of such monomers in any proportion, said polymer being oil soluble and having a number average molecular weight in the range of about 1,000 to 50,000, preferably about 15,000 to about 5,000 molecular weight.
• Molecular weights can be measured by cryoscopic methods or by vapor phase osmometry, for example by using a Mechrolab Vapor Phase Osmometer Model 310A.
• the unsaturated monomers, copolymerizable with ethylene include unsaturated acids, acid anhydrides, and mono and diesters of the general formula:
• R is hydrogen or methyl; R, is a-OOCR, or-CO0R, group wherein R is hydrogen or a C, to C preferably a C, to C, straight or branched chain alkyl group and R, is hydrogen OR-CO0R,.
• the monomer, when R, to R, are hydrogen and R, is-00C& includes vinyl alcohol esters of C, to C monocarboxylic acids. Examples of such esters include vinyl acetate, vinyl isobutyrate, vinyl laurate, vinyl myristate, vinyl palmitate, etc.
• esters include C, Oxo alcohol acrylate, methyl acrylate, methyl methacrylate, lauryl acrylate, isobutyl methacrylate, palmityl alcohol ester of alpha-methylacrylic acid, C Oxo alcohol esters of methacrylic acid, etc.
• monomers wherein R, is hydrogen and R, and R, are-00CR, groups include mono C 0x0 alcohol fumarate, di-C, Oxo alcohol fumarate, di-isopropyl maleate; di-lauryl fumarate; ethyl methyl fumarate, fumaric acid, maleic acid, etc.
• unsaturated monomers copolymerizable with ethylene to prepare pour point depressants or flow improvers useful in this invention include C, to C, branched chain or straight-chain alpha monoolef'tns, as for example propylene, noctene-l Z-ethyl decene-l n-decenel etc.
• a copolymer of 3m 40 moles of ethylene with one mole of a mixture of 30 to 99 mole percent of unsaturated ester and 70 to 1 mole percent of olefin could be used.
• copolymers that are formed are random copolymers consisting primarily of an ethylene polymer backbone along which are distributed side chains of hydrocarbon or oxy-substituted hydrocarbon.
• the Oxo alcohols used in preparing the esters mentioned above are isomeric mixtures of branched chain aliphatic primarv alcohols prepared from olefins, such as polymers and copolymers of C to C. monoolefins, reacted with carbon monoxide and hydrogen in the presence of a cobalt-containing catalyst such as cobalt carbonyl, at temperatures of about 300 to 400 F., under pressures of about 1,000 to 3,000 p.s.i., to form aldehydes. The resulting aldehyde product is then hydrogenated to form the x0 alcohol, the latter being recovered by distillation from the hydrogenated product.
• olefins such as polymers and copolymers of C to C. monoolefins
• cobalt-containing catalyst such as cobalt carbonyl
• any of the known methods for polymer preparation can be used in preparing the copolymer flow improver or pour depressant, including the techniques taught for ethylene-vinyl ester polymerizations in U.S. Pat. Nos. 3,048,479, 3,131,168, 3,093,623 and 3,254,063.
• a particularly useful technique is as follows: Solvent and a portion (e.g. to 50 percent of the total amount to be reacted) of each of the unsaturated monomers, that is to be copolymerized with the ethylene are charged to a stainless steel pressure vessel which is equipped with a stirrer. The temperature of the pressure vessel is then brought to reaction temperature and pressured to the desired pressure with ethylene.
• a catalyst which can be dissolved in a solvent to aid in handling, and additional amounts of the comonomer or comonomers are added to the vessel periodically or continuously during the reaction time. Also during this reaction time, as ethylene is consumed in the polymerization, additional ethylene is supplied through a pressure-controlling regulator so as to maintain the desired reaction pressure fairly constant at all times. Following the completion of the reaction, the liquid phase of the contents of the pressure vessel is distilled to remove the solvent and other volatile constituents of the reacted mixture, leaving the polymer as residue. in general, based upon 100 parts by weight of polymer to be produced, about 100 to 600 parts by weight of solvent, and about 1 to parts by weight of catalyst, will be used.
• the catalyst, or promoter will generally be of the free radical type, including organic peroxide types such as benzoyl peroxide, diacetyl peroxide, ditertiary butyl peroxide, dicumyl peroxide, tertiary butyl perbenzoate, di-lauroyl peroxide, tbutyl hydroperoxide, and also such non-peroxy compounds as azo-bis-isobutyronitrile, and the like.
• organic peroxide types such as benzoyl peroxide, diacetyl peroxide, ditertiary butyl peroxide, dicumyl peroxide, tertiary butyl perbenzoate, di-lauroyl peroxide, tbutyl hydroperoxide, and also such non-peroxy compounds as azo-bis-isobutyronitrile, and the like.
• the solvent can be any nonreactive organic solvent for furnishing a liquid phase reaction, preferably a hydrocarbon solvent such as benzene, hexane, or the like.
• the solvent should of course, be one that will not poison the catalyst or otherwise interfere with the reaction.
• Temperatures and pressures employed may vary widely. For example, depending partly on the decomposition temperature of the catalyst, the temperature may range from 100 to 450 F., with pressures of 500 to 30,000 p.s.i.g. However, usually the temperature will range between about 160 and about 350 F. Relatively moderate pressures of 700 to about 3,000 p.s.i.g. will be used with vinyl esters such as vinyl acetate, whereas with esters that have a lower reactivity to ethylene, such as methyl methacrylate, somewhat higher pressures, e.g. 3,000 to 10,000 p.s.i.g. are more satisfactory.
• a superatmospheric pressure is employed which is at least sufi'lcient to maintain a liquid phase medium under the reaction conditions, and is sufficient to maintain the desired concentration of ethylene in solution in the solvent.
• this pressure is attained by maintaining a continuous pressure on the reaction chamber through controlling the inlet feed of ethylene.
• the time of reaction will generally be within 1 to 10 hours, the reaction time being usually interrelated with the reaction temperature and pressure, and will also vary with the particular catalyst used.
• the pour point depressant or flow improver is generally used in a concentration in the range of from about 0.001 to about 2 weight percent, preferably from about 0.005 to about 0.5 percent by weight, based on the weight of the fuel oil being treated.
• the specific copolymer of ethylene and vinyl ester used in the working examples of the invention and referred to as flow improver A consisted of about 65 weight percent of ethylene and about 35 weight percent of vinyl acetate, and the copolymer had a number average molecular weight of about 2,000 as measured by vapor phase osmometry.
• the copolymer was prepared by copolymerizing ethylene and vinyl acetate,
• a 3-liter stirred autoclave is charged with 1,150 ml. of benzene as solvent and 40 ml. of vinyl acetate.
• the vapor space of the autoclave is first purged with a stream of nitrogen, followed by a stream of ethylene.
• the autoclave is heated to about 300 F. while ethylene is pressured into the autoclave until a pressure of 950 p.s.i.g. is reached. Then, while maintaining a temperature of about 300 F. and 950 p.s.i.g.
• Flow improver B referred to in the examples was prepared by the same general method as flow improver A, using ethylene, vinyl acetate, and a mixture of a-monoolefins having a range of 12 to 16 carbon atoms.
• the vinyl acetate and mixed olefins were fed into the reactor together during the course of the reaction. Specifically the initial charge to the reactor was 670 ml. of benzene and 32 ml. of vinyl acetate, the reaction pressure was 900 p.s.i.g., the reaction temperature was 220 F., the catalyst was lauryl peroxide, the mixture of 80 weight percent vinyl acetate and 20 weight percent mixed olefins was injected at the rate of 80 ml. per hour for minutes, and the total reaction time was minutes. The yield was 255 grams of copolymer. The copolymer in 47 weight percent solution in kerosene had a viscosity of 136 cs. at 100 F.
• Flow improver C was a copolymer of 22 weight percent vinyl acetate, 8 weight percent of C Oxo alcohol diesters of fumaric acid, and 70 weight percent of ethylene, the copolymer having a number average molecular weight of 2,400 as measured by vapor phase osmometry.
• Flow improver D referred to in the examples was a copolymer of ethylene and isobutyl acrylate of 2,400 number average molecular weight, the copolymer having about 7.2 ethylene units per mol of isobutyl methacrylate.
• EXAMPLE 1 in this example two paraffin wax cuts were employed, hereinafter referred to as wax l and wax ll.
• Wax l was obtained by dewaxing a light paraffinic distillate obtained from a San Joaquin waxy crude oil.
• Wax 11 was obtained by dewaxing the composedte obtained from the phenol extraction of a neutral parafiinic distillate having a 100 F. viscosity of about 75 S.U.S.
• Fuel oil blends were prepared by adding various weight perboiling point and 15 volume percent of heavy virgin naphtha centages of the flow improvers described above to either of boiling in the range of 290 and 430 F. is improved in lowtwo fuel oils, identified as fuel oils M and N, respectively. In 10 temperature flow properties by adding thereto 0.1l weight some cases either wax l or wax II was added to the fuel oil and percent of flow improver B, described above, together with in other cases no wax was added.
• 0.7 weight percent of a paraffin wax fraction having the fol- Fuel oil M was a blend of 80 volume percent catalytic cycle lowing percentages of C, and C normal paraffins: l2.5-C distillate and 20 volume percent naphtha, and had an ASTM I 5 l l.8-C, l0. l-C 6.7-C 3.4-C 20C 0.9-C,
• this test consists of allowing the test oil to flow by 0 8 Wei ht ercem ofwax described in exam 1 gravity through a standard sized opening for a set period of g p p time.
• this fluidity test was carried out in the fol- M E 4 (Part lowing manner: A ZOO-milliliter sample of the oil is cooled at a controlled rate of 4 F. per hour until an oil temperature of 0 w f j' P'evwuslyodescnbedt a 9' f R is reached, the latter being the temperature at which mg an inmal boilmg point of 36 4 F., a percen t distillation the test is run.
• the oil is then permitted to flow by gravity of 535 and a final boflmg pomtoof a clfmd through a 30-mesh screen of 9 millimeters diameter for 25 Pf of +24 and a Pomt f +20 charactenzed seconds.
• the volume percentage of oil that has flowed w1th ⁇ espect to the heat of fusion of the first wax to through the screen at the end of this time is then measured.
• the flow and plugging test was run as follows: The middle distillate fuel (about 3,500 ml.) contained in a l-gallon can is cooled to a test temperature below the cloud point over 5 to 8 hours and maintained at this temperature for to hours.
• the precooled test probe consisting of 150 cm. of 4.8 mm.
• outside diameter (0.8 mm. wall) copper tubing fitted with an inlet machined from a l-inch brass cube is inserted into the fuel.
• the inlet is a right-angle cone, l-inch in diameter at the base, and at the top of the cone where it joins the upper tubing is an orifice one-sixteenth inch in diameter and one-sixteenth inch long.
• the fuel is drawn into and through the probe under 5 inches mercury vacuum, and its volume is measured in a suitable receiver.
• a pass is 90 percent or more of the sample flowing with a drop in the vacuum at the end of the test (signifying no wax plug in the line). If a plug occurs at the inlet, it is released by increasing the vacuum momentarily or with a wire. A borderline result is at least 90 percent over with one wax plug at the end or during the test. A failure is less than 90 percent over, or two wax plugs.
• test results obtained in the present example are shown in table 11, which follows:
• Blends were prepared by adding to portions of the fuel oil, plus the 0.015 weight percent of flow improver, 0.1 weight percent of various purified waxes 24, 28 and 36 carbon atoms, respectively.
• the heats of fusion of the heating oil and of the individual waxes were as follows, in calories per mole.
• the flow and plugging test was developed to measure and predict the flow behavior of middle distillate fuels at low temperatures, and was based upon extensive winter field test data. Good correlation between this test and actual field test results has been found.
• a sample of the cold, waxy fuel is drawn under vacuum through a length of copper tubing with conical inlet.
• the conical inlet serves as a wax packing device which increases the severity of the test as far as plugging the line is concerned.
• the flow rate through the copper tubing is a As shown by-the data in table 11, a 24 carbon atom paraffin wax was just borderline in improving the response of the fuel oil to the flow improver, while the higher molecular weight waxes were quite effective in this respect.
• EXAMPLE 6 A number of commercial parafiin waxes were evaluated for their efiect on improving the responsiveness of a middle distillate fuel oil to the addition of a flow improver. These waxes had the characteristics shownbelow in table 111.
• the heat of fusion of the first wax to precipitate from the fuel was calculated as 13,400 calories per mole, using the method described above.
• the test apparatus is essentially an hourglass-shaped device having upper and lower chambers connected by a brass tube 2.25 mm. (0.10 inch) in diameter and 12.5 mm. long connecting the two chambers.
• a thin aluminum disc initially separates the chambers.
• the lower chamber of the test instrument is filled with ml. of the fuel to be tested.
• the fuel is cooled to a temperature below the predetermined cloud point of the fuel.
• a reading is taken of the volume of fuel in the test instrument and the sample container is inverted.
• the disc is punctured so that oil is permitted to drain through the flow opening.
• percent recovery The percentage of oil that drains through the opening in a period of 3 minutes.
• an oil-soluble wax-modifying random copolymer of ethylene and at least one additional ethylenically unsaturated polymerizable monomer said copolymer having an average molecular weight of from about 1,000 to 50,000 and comprising about 3 to 40 molar proportions of ethylene per molar proportion of other monomers, said copolymer consisting primarily of an ethylene polymer backbone along which are distributed side chains of hydrocarbon or oxy-substituted hydrocarbon, said other monomers being selected from the group consisting of an alpha monoolefm of three to 16 carbon atoms; N-vinyl pyrrolidone; and an unsaturated acid, unsaturated acid anhydride, unsaturated monoester, or unsaturated diester, of the general formula:
• R is hydrogen or methyl;
• R is a -00CR, or-COOR, group wherein R is hydrogen or a C to C straight or branched chain alkyl group and R, is hydrogen or-COOR,
• a parafiin wax in an amount sufficient to incorporate into the said fuel oil from about 0.03 to about 2 weight percent of normal paraffinic hydrocarbons of number average molecular weight in the range of about 300 to 650, the molar heat of fusion of said added wax being greater than the molar heat of fusion of the first wax to separate from the said fuel when cooled.
• said added wax has a molar heat of fusion that is from wherein said added wax includes normal paraffin hydrocar- 3,000 to 11,000 calories per mole greater than the molar heat bons in the range of C to C inclusive. of fusion of said first wax that separates from said fuel.

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• 1968
  • 1968-09-17 US US760346A patent/US3620696A/en not_active Expired - Lifetime
• 1969
  • 1969-06-18 GB GB1266037D patent/GB1266037A/en not_active Expired

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