CA1263235A - Middle distillate compositions with improved low temperature flow properties - Google Patents
Middle distillate compositions with improved low temperature flow propertiesInfo
- Publication number
- CA1263235A CA1263235A CA000444122A CA444122A CA1263235A CA 1263235 A CA1263235 A CA 1263235A CA 000444122 A CA000444122 A CA 000444122A CA 444122 A CA444122 A CA 444122A CA 1263235 A CA1263235 A CA 1263235A
- Authority
- CA
- Canada
- Prior art keywords
- fuel
- vinyl ester
- boiling point
- final boiling
- wax
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
-
- 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
- C10L10/00—Use of additives to fuels or fires for particular purposes
- C10L10/14—Use of additives to fuels or fires for particular purposes for improving low temperature properties
-
- 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
Abstract
ABSTRACT
The flow properties of a distillate petroleum fuel oil whose 20% and 90% distillation points differ within the range of from 65 to 100°C, and/or whose 90% to final boiling point is 10 to 20°C is improved by the inclusion of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt % of the vinyl ester and having a number average molecular weight of 1000 to 6000.
The flow properties of a distillate petroleum fuel oil whose 20% and 90% distillation points differ within the range of from 65 to 100°C, and/or whose 90% to final boiling point is 10 to 20°C is improved by the inclusion of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt % of the vinyl ester and having a number average molecular weight of 1000 to 6000.
Description
~63235 Middle Distillate Compositions with Im~oved Low Temperature Flow Properties 1 Mineral oils containing paraffin wax have the characteristic of becoming less fluid as the temperature of the oil decreases. This loss of fluidity is due to the crystallization of the wax into plate-like crystals which eventually form a spongy mass entrapping the oil therein.
It has long been known that various composltions act as wax crystal modifiers when blended with waxy mineral oils. These compositions modify the size and shape of wax crystals and reduce the adhesive forces between the wax and oil in such a manner as to permit the oil to remain fluid at a lower temperature.
Various pour point depressants have been described in the literature and several of these are in commercial use. For example, U.S. Pat. No. 3,048,479 teaches the use of copolymers of ethylene and C3-C5 vinyl esters, e.g. vinyl acetate, as pour depressants for ` fuels, specifically heating oils, diesel and jet fuels. Hydrocarbon polymeric pour depressants based on ethylene and higher alpha-olefins; e.g. propylene, are also known. U.S. Patent 3,961,916 teaches the use of a mixture of copolymers, one of which is a wax crystal nucleator and the other a growth arrestor to control the size of the wax crystals.
It has long been known that various composltions act as wax crystal modifiers when blended with waxy mineral oils. These compositions modify the size and shape of wax crystals and reduce the adhesive forces between the wax and oil in such a manner as to permit the oil to remain fluid at a lower temperature.
Various pour point depressants have been described in the literature and several of these are in commercial use. For example, U.S. Pat. No. 3,048,479 teaches the use of copolymers of ethylene and C3-C5 vinyl esters, e.g. vinyl acetate, as pour depressants for ` fuels, specifically heating oils, diesel and jet fuels. Hydrocarbon polymeric pour depressants based on ethylene and higher alpha-olefins; e.g. propylene, are also known. U.S. Patent 3,961,916 teaches the use of a mixture of copolymers, one of which is a wax crystal nucleator and the other a growth arrestor to control the size of the wax crystals.
- 2 - ~2~ S
1 Similarly United Kingdom Patent 1263152 suggests that the size of the wax crystals may be controlled by using a copolymer having a lower degree of side chain branching.
With the increasing diversity in distillate fuels, types of fuel have emerged which cannot be treated by the existing additives or which require an uneconomi-cally high level of additive. One particular group of fuels that present such problems are those which have a relatively narrow boiling range. Fuels are frequently characterised by their Initial ~oiling Point, Final Boiling Point and the interim temperatures at which certain volume percentages of the initial fuel have distilled. Fuels whose 20% to 9Q% distillation point differ within the range of from 65 to 100C
especially 70 to 100C (ASTM D86) and 90~ boiling temperature is generally from 10 to 30C especially 10 to 25C of the final boiling point have been found particularly difficult to treat sometimes being virtually unaffected by additives or otherwise requiring very high levels of additive. All distillations referred to herein are according to ASTM D86 Furthermore with the increase in the cost of crude oil it has also become important for a refiner to increase 25 his procuction ot distillate fuels and to optimise _ 3 _ ~2~35 l his operations using what is known as sharp fraction-ation again resulting in distillate fuels that are difficult to treat with conventional additives or that require a treat level than is unacceptably high for the economic standpoint. Typical sharply ~raction-ated fuels have a 90% to final boiling point of 10 to 20C usually with a 20 to 90~ boiling range of 90 to 110C. Both types of fuel have final boiling points above 350C generally a final boiling point in the range 350C to 375C especially 350C to 370C.
The copolymers of ethylene and vinyl acetate which have found widespread use for improving the fiow of the previously widely available distillate fuels generally contained up to about 30 wt ~ vinyl acetate where the additive was used to control the size of wax crystals forming in the fuel or they contained around 36 wt % or more vinyl acetate where their prime function was to lower the pour point of the distillate fuel. We have not found either of these types of additive to be effective in the treatment of the narrow boiling and/or sharply fractionated fuels described above.
We~have, however, found that copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms containing from 32 to 35 wt ~ of the , ....
_ 4 _ ~2~3~35 l vinyl ester and having a number average molecular weight of from 1000 to 6000 are particularly effective in the treatment of these of fuels.
The present invention therefore provides the use as an additive for improving the flow properties of a distillate petroleum fuel oil whose 20~ and 90~
distillation points differ within the range of from 65 to 100C, and/or for improving the flow properties of a distillate fuel whose 90% to final boiling point is 10 to 20C of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing l to 4 carbon atoms containing 32 to 35 wt % of the vinyl ester and having a number average molecular weight of lO00 to 6000.
The present invention further provides a distillate fuel whose 20% and 90% distillation point differ by 65 to 100C and whose 90% boiling temperature is from 10 to 30C of the final boiling point and/or whose 90~ to final boiling point is 10 to 20~C and containing from 50 to 500 ppm (parts per million) of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt ~ of the vinyl ester and having a number average molecular weight of 1000 to 6000.
_ 5 ~63235 1 The copolymer of the ethylene and vinyl ester of the carboxylic acid may be a mixture of two copolymers such as those generally described in United States Patent 3,961,916 which may or may not contain the same vinyl ester. In particular we find that an additive combination containing at least 10 parts by weight of the growth arrestor for each part by weight of the wax crystal nucleator is suitable for treating this type of fuel. The mixture being particularly useful since it allows added flexibility.
A preferred embôdiment of the present invention therefore provides the use as an additive for improving the flow properties of a distillate petroleum fuel oil whose 20% to 90~ distillation points dlffer within the range of from 65 to 100C, and/or of a distillate fuel whose 90% boiling temperature is from 10 to 30C
preferably 10 to 20C of the final boiling point an additive comprising from 10 to 15 parts by weight of a synthetic polymeric material having the property of a wax growth arrestor in said fuel for each part of a synthetic polymeric material having the properties of a wax growth stimulator, said wax growth arrestor and - 6 - ~Z6323S
1 growth stimulator being copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms the average ester content of said copolymers being in the range 32 to 35 wt.% and the number average molecular weight thereof being in the range 1000 to 6000.
In a further embodiment the present invention provides a distillate fuel whose 20% to 90% boiling fraction differ in their boiling point by from 65 to 100C
and/or a distillate fuel whose 90% to final boiling point is 10 to 20C containing from 50 to 500 ppm parts per million of an additive mixture of 10 to 15 parts by weight of a synthetic polymeric material having the property of a wax growth arrestor in said fuel for each part of a synthetic polymeric material having the properties of a wax growth stimulator said growth arrestor and growth stimulator being copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms, the average ester content of said copolymers belng in the range 32 to 35 wt.% and the number average molecular weight thereof being in the range 1000 ~o 6000.
.
. ~ .
_ 7 ~ 3~35 1 The fuels whose 20~ to 90~ distillation points differ within the range 65 to 100C their 90% boiling temperature generally is from lO to 30C of the final boiling points generally have a final boiling point above 350C
usually between 350C and 375C more usually between 350C and 370C. The fuels whose 90% to final boiling point is 10 to 20C usually have a 20 to 90% distillation ranye of from 90 to 110C and also generally have final boiling points above 350C usually between 350C
and 375C more usually between 350C and 370C.
Where the additive is a mixture the wax growth stimulator or nucleator is a synthetic polymeric material which is soluble in the distillate at temper-atures substantially above the saturation temperature but on cooling o the distillate progressively separates out in the form of small particles as the temperature of the distillate approaches the saturation point, e.g. is cooled from a point slightly above (e.g. 10C
above; preferably about 5C above) said saturation temperature. The term "saturation temperature" is defined as the lowest temperature at which solute, e.g. wax, cannot be crystallized out of the solution even if known crystallization inducement methods are used. Whilst not known certainly it is believed that as cooling continues, additional nucleator particles separate out in a more or less continuous manner.
These additional particles act as nucleators for - 8 - 12~3~35 1 continued wax crystallization, which in effect, would prevent substantial supercooling of the distillate.
The advantages of having fresh nucleator particles formed continuously is that the supersaturation of the distillate with n-paraffins is kept at the lowest possible level thus facilitating a molecule of growth arrestor to build itself into the growth center of growing crystals and by so doing to stop the further growth.
The inhibitory effect of a growth arrester is believed to result from the presence of bulky groups in its molecule. Additional nucleator should separate out to replace the deactivated growth centers. The wax growth arrester is more soluble in said distillate than said nucleator and it acts as a growth arrester as the wax crystal forms.
The nucleator should not be insoluble in the distillate at elevated temperatures nor should it start to separate out at a temperature substantially above that at which wax crystalli~ation can occur. If nucleators separate out at a temperature substantially above the temperature at which crystalli~ation can occur, then they tend to settle at the bottom of the vessel holding the distillate, instead of remaining dispersed within the distillate. This factor is especially important when the distillate is subjected to repeated :
g 1 warming and cooling as during the warm and cool parts of a dav since it does not result in adequate redisper-sion of the nucleant particles in the distillate.
The synthetic polymeric materials used as wax growth stimulators and wax growth arresters may contain the same or different vinyl esters.
For the purpose of this invention, wax crystal growth stimu~ators, wax nucleators and nucleants for wax are all considered equivalent terms and are used inter-changeably.
Wax growth arresters (hereinafter sometimes referredto as wax arresters), generally include in their molecular structure wax-like polymethylene segments which are capable of building themselves into the lattice of the wax crystals at the point of lattice dislocation, and also contain bulky groups which prevent incorporation of further molecules of n-paraffins at the point of lattice dislocation and by so doing stop further growth of crystal.
A good synthetic polymeric wax nucleator, can be chosen by visually comparing a transparent container ~containing a 0.1 to 3.0 wt.% solution of the potential nucleator in a distillate to an identical container ~with the same distillate having no additive, as the temperature of the two materials is lowered. The onset 1263~3S
-- 1 o --1 of the wax crystallization from the distillate containing a polymeric material which has nucleator characteristics will occur at a higher temperature than that at which the crystallization will start in the absence of said nucleator. ~imilarly, a wax arrester usually is characterized by the ability to delay onset of crystalli2ation.
The synthetic polymers used as nucleating agents and as wax growth arresters are copolymers of ethylene and vinyl ester and may contain the same or different ester monomer.
With the preferred additive that is a mixture of polymers as described above the vinyl ester content and molecular weight are the average over the mixture.
The additive may however also be single polymer by which is meant material produced in a single polymer-isation. In this instance the materials may be obtained by the well known high pressure or solution polymerisation techniques that have previously been suggested ~or the production of ethylene vinyl ester, especially vinyl acetate copolymers for fuel additives.
Typical vinyl esters for both mixtures and single polymers include vinyl acetater vinyl propionate, and vinyl butyrate.
" ~;263235 l The rlow improvers when incorporated into the distillate fuels preferably are effective in:
l. maintaining these fuels fluid at the operating temperatures, 2. arresting the growth of separating wax crystals when the oils are submitted to slow cooling, i.e. 0.2F to 2F./hr, which are typical of the rates encountered when "oil in bulk" is exposed to atmospheric cooling.
0 3. arresting the growth of separating wax crystals when the oils are submitted to fast cooling, i.e. 10F. to 100F./hr/. which are typical of the rates encountered when relatively warm oil enters transfer lines and is there suddenly exposed to low temperatures.
All three above-quoted criteria are desired in order to assure that a fuel is pumpable and filterable under the conditions of its distribution and it use.
As mentioned where mixtures of polymers are used the molecular weight is the average of the two polymers and in general, the preferred number average molecular weight (VPO) for the nucleator will be within the range of 500-6000, more preferably 1200-6000. Specifically, ~ for example, a relatively low molecular weight ethylene-vinyl ester copolymer with a relatively high vinylester content has been found to act as a wax growth - 12 ~ ~2~32~5 l arrester. On the other handl a relatively high molecular weight copolymer of ethylene with a vinyl ester which copolymer has a relatively low content of vinyl ester acts ais a nucleating agent. Even more specifically, blends containing ethylene/vinyl acetate copolymers of number average molecular weights from 1200-6000 (VPO) with vinyl acetate contents of about 32-50 wt.% (e.g. about 11 to 25 mole % ester) as the wax arresters and ethylene/vinyl acetate copolymers of about S00-10,000 (VPO) number average molecular weight with qinyl acetate comonomer proportions by weight of 1-30 wt.% (e.g. about 0.3 to 12 mole % ester) as the wax growth stimulators have been found to be highly effective. Where the nucleant is an ethylene/vinyl acetate copolymer its number average molecular weight is preferably at least 500, preferably 1000, higher and/or the ester content at least 5% lower than the corresponding property of the wax growth arrester.
All molecular weights specified herein are "number average molecular weights", which are molecular ~weights as measured by Vapor Phase Osmometry (VPO), e.g. using Mechrolab Vapor Phase Osmometer 301A. The vinyl acetate cantents are determined by saponifica~ion.
:
_ 13 _ ~ ~ ~3~35 1 Thus, relative to the growth arrester, the nucleator can comprise an ethylene-vinyl acetate copolymer of a higher molecular weight if the vinyl acetate content of both polymeric materials is about equal. Where two synthetic polymers are used they may be made separately or they can be made consecutively in one batch by varying the reaction conditions. Thus, the reaction conditions can be selected so that the initial polymerization reaction produces a polymer having primarily nucleator characteristics and the reaction conditions can be changed to produce a polymer having primarily wax growth arresting properties or vice versa. In this manner, a mixture of polymers can be produced having both types of functions.
In the specific embodiment of the invention which employs two different copolymers of ethylene and vinyl acetate the relationships between the concentration of vinyl acetate in the copolymer and molecular weight of the copolymers are important since they are factors which determines the role of the particular ~copolymer in the fuel. That is, they determine, given the other polymer properties are similar whether or not the copolymer as a whole will be performing within the composition as a wax arrester or as a wax nucleating agent.~ Thus, very generally as a rule of thumb, the nucleating agents~should have relatively long poly-.
- 14 - ~ ~63~35 1 methylene segments, and so as these synthetic polymers approach low molecular weight ranges, the proportion of vinyl acetate should also decrease. On the other hand, as the molecular weight increases, the proportion of vinyl acetate should also increase.
Thus, the specific wax nucleating agents will comprise a copoly~er of ethylene and a relatively low proportion of vinyl acetate with a relatively high molecular weight.
The wax arrester on the other hand will, in general, be a relatively low molecular weight copolymer of a relatively high vinyl acetate content since the function of wax arresting depends more on the presence of bulky groups, such as ester groups, attached to the backbone of the molecule of the copolymer.
Although the separate copolymers may be blended directly in the fuel, it will normally be found desirable to prepare a concentrate. This may be effected by first associating each with a separate solvent, but most preferably by dissolving each in a common solvent. Thus, both the preferred relatively lower molecular weight high vinyl acetate (second) copolymer and the preferred first , the relatively high molecular weight low vinyl acetate copolymer, may be dissolved ln a kerosene or heavy aromatic naphtha.
Preferred~concentrates will contain 5-60%, preferably ~:
_ 15 _ ~ ~63235 1 10-50% total copolymer with the balance being a hydrocarbon oil solvent.
The arrester copolymers may be prepared by known procedures employing free-radical initiators, preferably organic peroxide compounds. Suitable procedures are high temperature and high pressure processes or the solution processes U.S~ specifications, such as U.S.
Pat. Nos. 3~048,479 or 3,093,623 and United Kingdom Patent Specification 1263152.
In one aspect the fuels to which the present invention relates are diffïcult to treat with conventional additives because of the relatively narrow boiling range of the 20% to 90~ degree fraction of the fuel, the 90% fraction boiling from 65 to 100~C above that of the 20~ fraction and/or because of the relatively small gap between the 90~ boiling point and the final boiling point of less than 25~C and even, in some instances less than 20C.
Desirably, there is present a total of 0.001% to 0.5%
20 by weight of additive, based on the weight of fuel;
preferably 0.005 to 0.1%, most preferably 0.01 to 0.04%, all percents being weight percents. Where a mixture is used the pol~meric materials are used in - 16 ~ ~2~35 l ratios of 10 to 15 parts by weight of growth arrester, per part of the nucleator.
The present invention is illustrated by the following - Examples in which an additive of the present invention (additive A) was an oil solution containinq 63 wt.% of a combination of polymers comprising 13 parts by weight of a wax crystal growth arrestor comprising an ethylene vinyl acetate copolymer of number average molecular weight 2500 and vinyl acetate content of 36 wt.% and 1 part by weight of wax crystal simulator of number average molecular weight 3500 and a vinyl acetate content of about 13 wt.% Additive B
was an oil solution containing 45 wt.% of an additive combination of 3 parts by weight of the abovementioned wax crystal growth arrestor and 1 part of the wax crystal simulator according to United States Patent 3961916. Additive C is 50 wt.% solution in oil of an ethylene acetate copolymer of number average molecular weight 2000 and vinyl acetate content 30 wt.%.
-- l7 12f~235 1 The fuels used in the Examples were as follows:
Initial 20% 90~ Final B.P. B~P. B.P. B.P.
C C C C
Fuel 1 200 248 334 360 Fuel 2 228 280 351 374 ~uel 3 220 266 346 367 Fuel 4 224 268 341 359 Fuel 5 221 259 331 361 Fuel 6 244 264 336 360 10 Fuel 7 163 240 344 362 Fuel 8 160 234 344 358 Fuel 9 200 257 336 362 Fuel 10 213 264 338 360 In the Examples the Wax Crystal Size at Fast Cooling Rates is measured by the Cold Filter Plugging Point test (CFPP). This test is carried out by the procedure described in "Journal of the Institute of Petroleum", Volume 52, No. 510, June 1966, pp. 173-185. In brief, the~CFPP test is carried out with a 45 ml sample of ,, the oil to be tested. The oil placed in the ASTM
~cloud point jar is cooled in a bath maintained at about --30F. Every two degrees drop in temperature, starting from 4F. above the cloud point, the oil :
is forced at a suction of 8 inches of water through a filter element provided with a 350 mesh screen into a ~ plpette to a marX indicating a volume of 20 ml., at : ~ ;
~63235 1 which time the oil is allowed to return by gravity flow to the cooling chamber. The test is repeated with each 2C drop in oil temperature until the oil fails to fill the pipette in a period of 60 seconds to the aforesaid mark. The results of the test are reported as the Cold Filter Plugging Point which is the highest temperature at which the oil fails to fill the pipette.
The amounts of Additive A, Additive B and Additive C
required to achieve a 6C, 8C and 10C reduction in the temperature at which these fuels would pass the CFPP test were determined to be as follows:
Fuel 6C 8C 10C
Additive Additive Additive ~eduction Reductlon A B C A B C A B C
1 410 760 700 5601050 not 7001360 not possible possible 2 130 400 440 l90 540 620 250 650 n
1 Similarly United Kingdom Patent 1263152 suggests that the size of the wax crystals may be controlled by using a copolymer having a lower degree of side chain branching.
With the increasing diversity in distillate fuels, types of fuel have emerged which cannot be treated by the existing additives or which require an uneconomi-cally high level of additive. One particular group of fuels that present such problems are those which have a relatively narrow boiling range. Fuels are frequently characterised by their Initial ~oiling Point, Final Boiling Point and the interim temperatures at which certain volume percentages of the initial fuel have distilled. Fuels whose 20% to 9Q% distillation point differ within the range of from 65 to 100C
especially 70 to 100C (ASTM D86) and 90~ boiling temperature is generally from 10 to 30C especially 10 to 25C of the final boiling point have been found particularly difficult to treat sometimes being virtually unaffected by additives or otherwise requiring very high levels of additive. All distillations referred to herein are according to ASTM D86 Furthermore with the increase in the cost of crude oil it has also become important for a refiner to increase 25 his procuction ot distillate fuels and to optimise _ 3 _ ~2~35 l his operations using what is known as sharp fraction-ation again resulting in distillate fuels that are difficult to treat with conventional additives or that require a treat level than is unacceptably high for the economic standpoint. Typical sharply ~raction-ated fuels have a 90% to final boiling point of 10 to 20C usually with a 20 to 90~ boiling range of 90 to 110C. Both types of fuel have final boiling points above 350C generally a final boiling point in the range 350C to 375C especially 350C to 370C.
The copolymers of ethylene and vinyl acetate which have found widespread use for improving the fiow of the previously widely available distillate fuels generally contained up to about 30 wt ~ vinyl acetate where the additive was used to control the size of wax crystals forming in the fuel or they contained around 36 wt % or more vinyl acetate where their prime function was to lower the pour point of the distillate fuel. We have not found either of these types of additive to be effective in the treatment of the narrow boiling and/or sharply fractionated fuels described above.
We~have, however, found that copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms containing from 32 to 35 wt ~ of the , ....
_ 4 _ ~2~3~35 l vinyl ester and having a number average molecular weight of from 1000 to 6000 are particularly effective in the treatment of these of fuels.
The present invention therefore provides the use as an additive for improving the flow properties of a distillate petroleum fuel oil whose 20~ and 90~
distillation points differ within the range of from 65 to 100C, and/or for improving the flow properties of a distillate fuel whose 90% to final boiling point is 10 to 20C of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing l to 4 carbon atoms containing 32 to 35 wt % of the vinyl ester and having a number average molecular weight of lO00 to 6000.
The present invention further provides a distillate fuel whose 20% and 90% distillation point differ by 65 to 100C and whose 90% boiling temperature is from 10 to 30C of the final boiling point and/or whose 90~ to final boiling point is 10 to 20~C and containing from 50 to 500 ppm (parts per million) of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt ~ of the vinyl ester and having a number average molecular weight of 1000 to 6000.
_ 5 ~63235 1 The copolymer of the ethylene and vinyl ester of the carboxylic acid may be a mixture of two copolymers such as those generally described in United States Patent 3,961,916 which may or may not contain the same vinyl ester. In particular we find that an additive combination containing at least 10 parts by weight of the growth arrestor for each part by weight of the wax crystal nucleator is suitable for treating this type of fuel. The mixture being particularly useful since it allows added flexibility.
A preferred embôdiment of the present invention therefore provides the use as an additive for improving the flow properties of a distillate petroleum fuel oil whose 20% to 90~ distillation points dlffer within the range of from 65 to 100C, and/or of a distillate fuel whose 90% boiling temperature is from 10 to 30C
preferably 10 to 20C of the final boiling point an additive comprising from 10 to 15 parts by weight of a synthetic polymeric material having the property of a wax growth arrestor in said fuel for each part of a synthetic polymeric material having the properties of a wax growth stimulator, said wax growth arrestor and - 6 - ~Z6323S
1 growth stimulator being copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms the average ester content of said copolymers being in the range 32 to 35 wt.% and the number average molecular weight thereof being in the range 1000 to 6000.
In a further embodiment the present invention provides a distillate fuel whose 20% to 90% boiling fraction differ in their boiling point by from 65 to 100C
and/or a distillate fuel whose 90% to final boiling point is 10 to 20C containing from 50 to 500 ppm parts per million of an additive mixture of 10 to 15 parts by weight of a synthetic polymeric material having the property of a wax growth arrestor in said fuel for each part of a synthetic polymeric material having the properties of a wax growth stimulator said growth arrestor and growth stimulator being copolymers of ethylene and vinyl esters of carboxylic acids containing from 1 to 4 carbon atoms, the average ester content of said copolymers belng in the range 32 to 35 wt.% and the number average molecular weight thereof being in the range 1000 ~o 6000.
.
. ~ .
_ 7 ~ 3~35 1 The fuels whose 20~ to 90~ distillation points differ within the range 65 to 100C their 90% boiling temperature generally is from lO to 30C of the final boiling points generally have a final boiling point above 350C
usually between 350C and 375C more usually between 350C and 370C. The fuels whose 90% to final boiling point is 10 to 20C usually have a 20 to 90% distillation ranye of from 90 to 110C and also generally have final boiling points above 350C usually between 350C
and 375C more usually between 350C and 370C.
Where the additive is a mixture the wax growth stimulator or nucleator is a synthetic polymeric material which is soluble in the distillate at temper-atures substantially above the saturation temperature but on cooling o the distillate progressively separates out in the form of small particles as the temperature of the distillate approaches the saturation point, e.g. is cooled from a point slightly above (e.g. 10C
above; preferably about 5C above) said saturation temperature. The term "saturation temperature" is defined as the lowest temperature at which solute, e.g. wax, cannot be crystallized out of the solution even if known crystallization inducement methods are used. Whilst not known certainly it is believed that as cooling continues, additional nucleator particles separate out in a more or less continuous manner.
These additional particles act as nucleators for - 8 - 12~3~35 1 continued wax crystallization, which in effect, would prevent substantial supercooling of the distillate.
The advantages of having fresh nucleator particles formed continuously is that the supersaturation of the distillate with n-paraffins is kept at the lowest possible level thus facilitating a molecule of growth arrestor to build itself into the growth center of growing crystals and by so doing to stop the further growth.
The inhibitory effect of a growth arrester is believed to result from the presence of bulky groups in its molecule. Additional nucleator should separate out to replace the deactivated growth centers. The wax growth arrester is more soluble in said distillate than said nucleator and it acts as a growth arrester as the wax crystal forms.
The nucleator should not be insoluble in the distillate at elevated temperatures nor should it start to separate out at a temperature substantially above that at which wax crystalli~ation can occur. If nucleators separate out at a temperature substantially above the temperature at which crystalli~ation can occur, then they tend to settle at the bottom of the vessel holding the distillate, instead of remaining dispersed within the distillate. This factor is especially important when the distillate is subjected to repeated :
g 1 warming and cooling as during the warm and cool parts of a dav since it does not result in adequate redisper-sion of the nucleant particles in the distillate.
The synthetic polymeric materials used as wax growth stimulators and wax growth arresters may contain the same or different vinyl esters.
For the purpose of this invention, wax crystal growth stimu~ators, wax nucleators and nucleants for wax are all considered equivalent terms and are used inter-changeably.
Wax growth arresters (hereinafter sometimes referredto as wax arresters), generally include in their molecular structure wax-like polymethylene segments which are capable of building themselves into the lattice of the wax crystals at the point of lattice dislocation, and also contain bulky groups which prevent incorporation of further molecules of n-paraffins at the point of lattice dislocation and by so doing stop further growth of crystal.
A good synthetic polymeric wax nucleator, can be chosen by visually comparing a transparent container ~containing a 0.1 to 3.0 wt.% solution of the potential nucleator in a distillate to an identical container ~with the same distillate having no additive, as the temperature of the two materials is lowered. The onset 1263~3S
-- 1 o --1 of the wax crystallization from the distillate containing a polymeric material which has nucleator characteristics will occur at a higher temperature than that at which the crystallization will start in the absence of said nucleator. ~imilarly, a wax arrester usually is characterized by the ability to delay onset of crystalli2ation.
The synthetic polymers used as nucleating agents and as wax growth arresters are copolymers of ethylene and vinyl ester and may contain the same or different ester monomer.
With the preferred additive that is a mixture of polymers as described above the vinyl ester content and molecular weight are the average over the mixture.
The additive may however also be single polymer by which is meant material produced in a single polymer-isation. In this instance the materials may be obtained by the well known high pressure or solution polymerisation techniques that have previously been suggested ~or the production of ethylene vinyl ester, especially vinyl acetate copolymers for fuel additives.
Typical vinyl esters for both mixtures and single polymers include vinyl acetater vinyl propionate, and vinyl butyrate.
" ~;263235 l The rlow improvers when incorporated into the distillate fuels preferably are effective in:
l. maintaining these fuels fluid at the operating temperatures, 2. arresting the growth of separating wax crystals when the oils are submitted to slow cooling, i.e. 0.2F to 2F./hr, which are typical of the rates encountered when "oil in bulk" is exposed to atmospheric cooling.
0 3. arresting the growth of separating wax crystals when the oils are submitted to fast cooling, i.e. 10F. to 100F./hr/. which are typical of the rates encountered when relatively warm oil enters transfer lines and is there suddenly exposed to low temperatures.
All three above-quoted criteria are desired in order to assure that a fuel is pumpable and filterable under the conditions of its distribution and it use.
As mentioned where mixtures of polymers are used the molecular weight is the average of the two polymers and in general, the preferred number average molecular weight (VPO) for the nucleator will be within the range of 500-6000, more preferably 1200-6000. Specifically, ~ for example, a relatively low molecular weight ethylene-vinyl ester copolymer with a relatively high vinylester content has been found to act as a wax growth - 12 ~ ~2~32~5 l arrester. On the other handl a relatively high molecular weight copolymer of ethylene with a vinyl ester which copolymer has a relatively low content of vinyl ester acts ais a nucleating agent. Even more specifically, blends containing ethylene/vinyl acetate copolymers of number average molecular weights from 1200-6000 (VPO) with vinyl acetate contents of about 32-50 wt.% (e.g. about 11 to 25 mole % ester) as the wax arresters and ethylene/vinyl acetate copolymers of about S00-10,000 (VPO) number average molecular weight with qinyl acetate comonomer proportions by weight of 1-30 wt.% (e.g. about 0.3 to 12 mole % ester) as the wax growth stimulators have been found to be highly effective. Where the nucleant is an ethylene/vinyl acetate copolymer its number average molecular weight is preferably at least 500, preferably 1000, higher and/or the ester content at least 5% lower than the corresponding property of the wax growth arrester.
All molecular weights specified herein are "number average molecular weights", which are molecular ~weights as measured by Vapor Phase Osmometry (VPO), e.g. using Mechrolab Vapor Phase Osmometer 301A. The vinyl acetate cantents are determined by saponifica~ion.
:
_ 13 _ ~ ~ ~3~35 1 Thus, relative to the growth arrester, the nucleator can comprise an ethylene-vinyl acetate copolymer of a higher molecular weight if the vinyl acetate content of both polymeric materials is about equal. Where two synthetic polymers are used they may be made separately or they can be made consecutively in one batch by varying the reaction conditions. Thus, the reaction conditions can be selected so that the initial polymerization reaction produces a polymer having primarily nucleator characteristics and the reaction conditions can be changed to produce a polymer having primarily wax growth arresting properties or vice versa. In this manner, a mixture of polymers can be produced having both types of functions.
In the specific embodiment of the invention which employs two different copolymers of ethylene and vinyl acetate the relationships between the concentration of vinyl acetate in the copolymer and molecular weight of the copolymers are important since they are factors which determines the role of the particular ~copolymer in the fuel. That is, they determine, given the other polymer properties are similar whether or not the copolymer as a whole will be performing within the composition as a wax arrester or as a wax nucleating agent.~ Thus, very generally as a rule of thumb, the nucleating agents~should have relatively long poly-.
- 14 - ~ ~63~35 1 methylene segments, and so as these synthetic polymers approach low molecular weight ranges, the proportion of vinyl acetate should also decrease. On the other hand, as the molecular weight increases, the proportion of vinyl acetate should also increase.
Thus, the specific wax nucleating agents will comprise a copoly~er of ethylene and a relatively low proportion of vinyl acetate with a relatively high molecular weight.
The wax arrester on the other hand will, in general, be a relatively low molecular weight copolymer of a relatively high vinyl acetate content since the function of wax arresting depends more on the presence of bulky groups, such as ester groups, attached to the backbone of the molecule of the copolymer.
Although the separate copolymers may be blended directly in the fuel, it will normally be found desirable to prepare a concentrate. This may be effected by first associating each with a separate solvent, but most preferably by dissolving each in a common solvent. Thus, both the preferred relatively lower molecular weight high vinyl acetate (second) copolymer and the preferred first , the relatively high molecular weight low vinyl acetate copolymer, may be dissolved ln a kerosene or heavy aromatic naphtha.
Preferred~concentrates will contain 5-60%, preferably ~:
_ 15 _ ~ ~63235 1 10-50% total copolymer with the balance being a hydrocarbon oil solvent.
The arrester copolymers may be prepared by known procedures employing free-radical initiators, preferably organic peroxide compounds. Suitable procedures are high temperature and high pressure processes or the solution processes U.S~ specifications, such as U.S.
Pat. Nos. 3~048,479 or 3,093,623 and United Kingdom Patent Specification 1263152.
In one aspect the fuels to which the present invention relates are diffïcult to treat with conventional additives because of the relatively narrow boiling range of the 20% to 90~ degree fraction of the fuel, the 90% fraction boiling from 65 to 100~C above that of the 20~ fraction and/or because of the relatively small gap between the 90~ boiling point and the final boiling point of less than 25~C and even, in some instances less than 20C.
Desirably, there is present a total of 0.001% to 0.5%
20 by weight of additive, based on the weight of fuel;
preferably 0.005 to 0.1%, most preferably 0.01 to 0.04%, all percents being weight percents. Where a mixture is used the pol~meric materials are used in - 16 ~ ~2~35 l ratios of 10 to 15 parts by weight of growth arrester, per part of the nucleator.
The present invention is illustrated by the following - Examples in which an additive of the present invention (additive A) was an oil solution containinq 63 wt.% of a combination of polymers comprising 13 parts by weight of a wax crystal growth arrestor comprising an ethylene vinyl acetate copolymer of number average molecular weight 2500 and vinyl acetate content of 36 wt.% and 1 part by weight of wax crystal simulator of number average molecular weight 3500 and a vinyl acetate content of about 13 wt.% Additive B
was an oil solution containing 45 wt.% of an additive combination of 3 parts by weight of the abovementioned wax crystal growth arrestor and 1 part of the wax crystal simulator according to United States Patent 3961916. Additive C is 50 wt.% solution in oil of an ethylene acetate copolymer of number average molecular weight 2000 and vinyl acetate content 30 wt.%.
-- l7 12f~235 1 The fuels used in the Examples were as follows:
Initial 20% 90~ Final B.P. B~P. B.P. B.P.
C C C C
Fuel 1 200 248 334 360 Fuel 2 228 280 351 374 ~uel 3 220 266 346 367 Fuel 4 224 268 341 359 Fuel 5 221 259 331 361 Fuel 6 244 264 336 360 10 Fuel 7 163 240 344 362 Fuel 8 160 234 344 358 Fuel 9 200 257 336 362 Fuel 10 213 264 338 360 In the Examples the Wax Crystal Size at Fast Cooling Rates is measured by the Cold Filter Plugging Point test (CFPP). This test is carried out by the procedure described in "Journal of the Institute of Petroleum", Volume 52, No. 510, June 1966, pp. 173-185. In brief, the~CFPP test is carried out with a 45 ml sample of ,, the oil to be tested. The oil placed in the ASTM
~cloud point jar is cooled in a bath maintained at about --30F. Every two degrees drop in temperature, starting from 4F. above the cloud point, the oil :
is forced at a suction of 8 inches of water through a filter element provided with a 350 mesh screen into a ~ plpette to a marX indicating a volume of 20 ml., at : ~ ;
~63235 1 which time the oil is allowed to return by gravity flow to the cooling chamber. The test is repeated with each 2C drop in oil temperature until the oil fails to fill the pipette in a period of 60 seconds to the aforesaid mark. The results of the test are reported as the Cold Filter Plugging Point which is the highest temperature at which the oil fails to fill the pipette.
The amounts of Additive A, Additive B and Additive C
required to achieve a 6C, 8C and 10C reduction in the temperature at which these fuels would pass the CFPP test were determined to be as follows:
Fuel 6C 8C 10C
Additive Additive Additive ~eduction Reductlon A B C A B C A B C
1 410 760 700 5601050 not 7001360 not possible possible 2 130 400 440 l90 540 620 250 650 n
3 420 700 - 500 850 - 520 820
4 7~0~ not 800 not 900 not Fssible Fssible Fssible 780 ~ " 840 " not n possible 7 570 - 900 620 ~ 950 710 - 1100 9 260 - not 370 - not 450 - not possible Fossible possible 530 -- 570 -- 600 ~ n ~63~5 , g 1 In a further series of experiments the amount of additive required to give a reduction of 6, 8 and 10C
in the CFPP value of various fuels was tested and compared with the amounts required for additives outside of the present invention.
The fuels used were: ~
Fuel No. IBP 20% 90~ F8P
17 222 260 32~ 354 and the additives used were A, 8 and C as used in the previous example together with Additives D to H as follows:
Wt. %
Vinyl Molecular Additives - Acetate Weight ~ D 34.8 ~~ 2650 ~ E 27.1 3170 - F 28.9 2590 G 28.2 2940 H 29.9 2300 ; The results are given in the following table.
2~cii3235 U U~1u~ ooo s~l~ oo!oou~oo ooo~ oc~r ~ ~ ~3~ Oo~ ~r~rer ~r~c~ o--~ ~ooo I~ r-~ ~ ,~ ~ r ~1 ~I ~ ~ ~ ~ ~ ~
'~1 LrlO - o o ooo ou~ ooo ooo ~o , ~ ) ~ ~ ~ ~ r o o t~ u~
o O ~ `u7 o ~ o O u~ o~o o ~n O o olo o o .~
~oo ~ u~ ~ r l~r ~ o o 0 0 0 0 0 O u1 O O 0 0 0 0 0 0 ~S 5 --~ ¦ e In ~ ~ O O O ~ A A . _ ~ ~ N ~J N N ~
0 U-l o u~ O O O~ O o O 00~ 00 ~O o~ 0 r--o o o o o 11 Il~ ~-- o O _. .
3 ~O O _ N ~ O O O O O O O O C ~ O O O O O O I~ U~ CO
mi ~C~cn C:t ~
~¢ ¦ Il') ~ UO~ ~ 11~ 0O C~ ~ ~ GOO r~ ~O ~ N N i~
~ o ~ gcoo ~coo ~a)o j~DCOo ~ 0 ~ o ~) Zl ~
~1 - ~ ~ el~ u~ ~ c~
l I
in the CFPP value of various fuels was tested and compared with the amounts required for additives outside of the present invention.
The fuels used were: ~
Fuel No. IBP 20% 90~ F8P
17 222 260 32~ 354 and the additives used were A, 8 and C as used in the previous example together with Additives D to H as follows:
Wt. %
Vinyl Molecular Additives - Acetate Weight ~ D 34.8 ~~ 2650 ~ E 27.1 3170 - F 28.9 2590 G 28.2 2940 H 29.9 2300 ; The results are given in the following table.
2~cii3235 U U~1u~ ooo s~l~ oo!oou~oo ooo~ oc~r ~ ~ ~3~ Oo~ ~r~rer ~r~c~ o--~ ~ooo I~ r-~ ~ ,~ ~ r ~1 ~I ~ ~ ~ ~ ~ ~
'~1 LrlO - o o ooo ou~ ooo ooo ~o , ~ ) ~ ~ ~ ~ r o o t~ u~
o O ~ `u7 o ~ o O u~ o~o o ~n O o olo o o .~
~oo ~ u~ ~ r l~r ~ o o 0 0 0 0 0 O u1 O O 0 0 0 0 0 0 ~S 5 --~ ¦ e In ~ ~ O O O ~ A A . _ ~ ~ N ~J N N ~
0 U-l o u~ O O O~ O o O 00~ 00 ~O o~ 0 r--o o o o o 11 Il~ ~-- o O _. .
3 ~O O _ N ~ O O O O O O O O C ~ O O O O O O I~ U~ CO
mi ~C~cn C:t ~
~¢ ¦ Il') ~ UO~ ~ 11~ 0O C~ ~ ~ GOO r~ ~O ~ N N i~
~ o ~ gcoo ~coo ~a)o j~DCOo ~ 0 ~ o ~) Zl ~
~1 - ~ ~ el~ u~ ~ c~
l I
Claims (18)
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for improving the flow properties of a distillate petroleum fuel having the following properties:
(a) the 20% and 90% distillation points differ within the range of from 65 to 100°C; and (b) the 90% to final boiling point is from 10 to 30°C;
said process comprising the incorporation in said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35-wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
(a) the 20% and 90% distillation points differ within the range of from 65 to 100°C; and (b) the 90% to final boiling point is from 10 to 30°C;
said process comprising the incorporation in said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35-wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
2. A process for improving the flow properties of a distillate petroleum fuel oil whose 90% to final boiling point is from 10 to 30°C;
said process comprising the incorporation in said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
said process comprising the incorporation in said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
3. The process of claim 1 wherein the fuel has a final boiling point in the range 350 to 375°C.
4. A process according to claim 1, 2 or 3, in which the additive is a mixture of two copolymers, one of which acts as a nucleator for wax and the other of which acts as a growth arrestor for wax crystals.
5. A process according to claim 1, 2 or 3, in which the additive is a mixture of two copolymers one of which acts as a nucleator for wax and the other of which acts as a growth-arrestor for wax crystals, said mixture containing at least 10 parts by weight of the growth arrestor for each part by weight of the nucleator.
6. A process according to claim 1, 2 or 3, wherein the vinyl ester is vinyl acetate.
7. The process of claim 2, wherein the fuel has a final boiling point in the range 350 to 375°C.
8. A process according to claim 7, in which the additive is a mixture of two copolymers, one of which acts as a nucleator for wax and the other of which acts as a growth arrestor for wax crystals.
9. A process according to claim 7, in which the additive is a mixture of two copolymers, one of which acts as a nucleator for wax and the other of which acts as a growth arrestor for wax crystals, said mixture containing at least 10 parts by weight of the growth arrestor for each part by weight of the nucleator.
10. A process according to claim 7, wherein the vinyl ester is vinyl acetate.
11, A process according to claim 1, wherein the 20% to 90% distillation range of the fuel is 70° to 100°C and the 90% to final boiling point is from 10° to 25°C.
12. A distillate fuel whose 20% and 90% distillation point differs by 65 to 100°C and whose 90% to final boiling point is from 10 to 30°C containing from 50 to 500 ppm of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing l to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
13. A distillate fuel according to claim 12 wherein the 20% to 90%
distillation range of the fuel oil is 70° to 100°C and the 90% to final boiling point is from 10° to 25°C.
distillation range of the fuel oil is 70° to 100°C and the 90% to final boiling point is from 10° to 25°C.
14 . A distillate fuel whose 90% to final boiling point is from 10 to 20°C
containing from 50 to 500 ppm of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
containing from 50 to 500 ppm of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
15. An additive concentrate suitable for incorporation into waxy distillate fuels having a final boiling point of at least 350°C., said concentrate comprising a solution in a hydrocarbon solvent of from 5 to 60 wt.%
of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing from 1 to 4 carbon atoms containing from 32 to 25 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing from 1 to 4 carbon atoms containing from 32 to 25 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
16. An additive concentrate according to claim 15 in which the copolymer of ethylene and the vinyl ester is a mixture of two copolymers, one of which acts as a nucleator for wax crystals and the other as a growth arrestor, the number average vinyl acetate content of the copolymers being in the range 32 to 35 wt.% and the number average molecular weight of the two copolymers being in the range 1000 to 6000,
17. A process for improving the flow properties of a waxy distillate fuel having a final boiling point of between 350°C and 375°C and wherein:
(a) the 20% and 90% distillation points dffer within the range of from 65 to 100°C and the 90% boiling temperature is from 10 to 30°C of the final boiling point; or (b) the 20 to 90% distillation points differ by 90 to 110°C and the 90% to final boiling point is 10 to 20°C;
said process comprising the incorporation into said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
(a) the 20% and 90% distillation points dffer within the range of from 65 to 100°C and the 90% boiling temperature is from 10 to 30°C of the final boiling point; or (b) the 20 to 90% distillation points differ by 90 to 110°C and the 90% to final boiling point is 10 to 20°C;
said process comprising the incorporation into said fuel of an additive comprising a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinyl ester and having a number average molecular weight of 1000 to 6000.
18. A waxy distillate fuel having a final boiling point of between 350°Cand 375°C and wherein:
(a) the 20% and 90% distillation points differ by 65 to 100°C and the 90%boiling temperature is from 10 to 30°C of the final boiling point; and (b) the 20% and 90% distillation points differ by 90 to 110°C and the 90%to final boiling point is 10 to 20°C;
said fuel containing from 50 to 500 ppm of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinly ester and having a number average molecular weight of 1000 to 6000.
(a) the 20% and 90% distillation points differ by 65 to 100°C and the 90%boiling temperature is from 10 to 30°C of the final boiling point; and (b) the 20% and 90% distillation points differ by 90 to 110°C and the 90%to final boiling point is 10 to 20°C;
said fuel containing from 50 to 500 ppm of a copolymer of ethylene and a vinyl ester of a carboxylic acid containing 1 to 4 carbon atoms containing 32 to 35 wt.% of the vinly ester and having a number average molecular weight of 1000 to 6000.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB838300016A GB8300016D0 (en) | 1983-01-04 | 1983-01-04 | Middle distillate compositions |
| GB83-00016 | 1983-01-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1263235A true CA1263235A (en) | 1989-11-28 |
Family
ID=10535834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000444122A Expired CA1263235A (en) | 1983-01-04 | 1983-12-22 | Middle distillate compositions with improved low temperature flow properties |
Country Status (14)
| Country | Link |
|---|---|
| EP (1) | EP0113581B2 (en) |
| JP (2) | JPS59136391A (en) |
| KR (1) | KR910004942B1 (en) |
| AT (1) | ATE80651T1 (en) |
| AU (1) | AU2305183A (en) |
| CA (1) | CA1263235A (en) |
| DD (2) | DD226901A5 (en) |
| DE (1) | DE3382624T3 (en) |
| DK (1) | DK164792C (en) |
| FI (1) | FI834887A (en) |
| GB (1) | GB8300016D0 (en) |
| IN (1) | IN159929B (en) |
| NO (1) | NO172650C (en) |
| NZ (1) | NZ206666A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6110238A (en) * | 1998-01-24 | 2000-08-29 | Clariant Gmbh | Process for improving the cold-flow properties of fuel oils |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8300016D0 (en) * | 1983-01-04 | 1983-02-09 | Exxon Research Engineering Co | Middle distillate compositions |
| JPS6270488A (en) * | 1985-09-24 | 1987-03-31 | Mitsubishi Petrochem Co Ltd | Additive of fuel oil and fuel oil improved in flowability |
| US5814110A (en) * | 1986-09-24 | 1998-09-29 | Exxon Chemical Patents Inc. | Chemical compositions and use as fuel additives |
| GB9213909D0 (en) * | 1992-06-30 | 1992-08-12 | Exxon Chemical Patents Inc | Oil additives and compositions |
| GB9213827D0 (en) * | 1992-06-30 | 1992-08-12 | Exxon Chemical Patents Inc | Oil additives and compositions |
| GB9725579D0 (en) | 1997-12-03 | 1998-02-04 | Exxon Chemical Patents Inc | Additives and oil compositions |
| GB9725581D0 (en) | 1997-12-03 | 1998-02-04 | Exxon Chemical Patents Inc | Additives and oil compositions |
| JP4796242B2 (en) * | 2001-05-25 | 2011-10-19 | 三洋化成工業株式会社 | Fluidity improver |
| JP4827798B2 (en) * | 2007-06-13 | 2011-11-30 | 三菱電機株式会社 | Remote controller for air conditioning, air conditioner and air conditioning system |
| CA3034201A1 (en) | 2018-01-25 | 2019-07-25 | Guilherme DOS SANTOS VIEIRA LIMA | Auxiliary system and method for starting or restarting the flow of gelled fluid |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3048479A (en) * | 1959-08-03 | 1962-08-07 | Exxon Research Engineering Co | Ethylene-vinyl ester pour depressant for middle distillates |
| US3093623A (en) * | 1960-01-05 | 1963-06-11 | Exxon Research Engineering Co | Process for the manufacture of improved pour depressants for middle distillates |
| DE1914756C3 (en) * | 1968-04-01 | 1985-05-15 | Exxon Research and Engineering Co., Linden, N.J. | Use of ethylene-vinyl acetate copolymers for petroleum distillates |
| US3961916A (en) * | 1972-02-08 | 1976-06-08 | Exxon Research And Engineering Company | Middle distillate compositions with improved filterability and process therefor |
| US3966428A (en) * | 1973-10-31 | 1976-06-29 | Exxon Research And Engineering Company | Ethylene backbone polymers in combination with ester polymers having long alkyl side chains are low viscosity distillate fuel cold flow improvers |
| US3884764A (en) * | 1974-03-25 | 1975-05-20 | Eastman Kodak Co | Method and composition for blood serum cholesterol analysis |
| GB1593672A (en) * | 1977-10-07 | 1981-07-22 | Exxon Research Engineering Co | Polymer combinations useful in distillate hydrocarbon oils to improve cold flow properties |
| DE2862158D1 (en) * | 1977-12-20 | 1983-02-17 | Ici Plc | Crude oil having improved cold flow properties |
| DE2837341C2 (en) * | 1978-08-26 | 1983-02-17 | Akzo Gmbh, 5600 Wuppertal | Process for the production of organic mono- and polyisocyanates by thermal cleavage of the hydrochlorides of trisubstituted ureas |
| JPS5854703B2 (en) * | 1979-10-04 | 1983-12-06 | 株式会社東芝 | Judgment circuit |
| JPS56103294A (en) * | 1980-01-23 | 1981-08-18 | Nippon Kemutetsuku Consulting Kk | Coal-containing slurry composition |
| JPS6017399B2 (en) * | 1980-04-07 | 1985-05-02 | 住友化学工業株式会社 | Additives for petroleum distillate fuel oil |
| EP0061894B1 (en) * | 1981-03-31 | 1985-09-11 | Exxon Research And Engineering Company | Two-component flow improver additive for middle distillate fuel oils |
| JPS58129096A (en) * | 1982-01-27 | 1983-08-01 | Mitsubishi Petrochem Co Ltd | Additive for fuel oil |
| GB8300016D0 (en) * | 1983-01-04 | 1983-02-09 | Exxon Research Engineering Co | Middle distillate compositions |
| JPH0247518A (en) * | 1988-08-10 | 1990-02-16 | Mitsubishi Electric Corp | Warm water apparatus |
| JPH0330637A (en) * | 1989-06-27 | 1991-02-08 | Taiyo Fishery Co Ltd | Method for improving body color of cultured fish |
-
1983
- 1983-01-04 GB GB838300016A patent/GB8300016D0/en active Pending
- 1983-12-21 NZ NZ206666A patent/NZ206666A/en unknown
- 1983-12-22 CA CA000444122A patent/CA1263235A/en not_active Expired
- 1983-12-22 DE DE3382624T patent/DE3382624T3/en not_active Expired - Fee Related
- 1983-12-22 AT AT83307869T patent/ATE80651T1/en not_active IP Right Cessation
- 1983-12-22 EP EP83307869A patent/EP0113581B2/en not_active Expired - Lifetime
- 1983-12-23 IN IN859/DEL/83A patent/IN159929B/en unknown
- 1983-12-30 KR KR1019830006322A patent/KR910004942B1/en not_active IP Right Cessation
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1984
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1992
- 1992-07-28 JP JP4201144A patent/JP2534818B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6110238A (en) * | 1998-01-24 | 2000-08-29 | Clariant Gmbh | Process for improving the cold-flow properties of fuel oils |
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| NO834889L (en) | 1984-07-05 |
| IN159929B (en) | 1987-06-13 |
| EP0113581B1 (en) | 1992-09-16 |
| NZ206666A (en) | 1987-06-30 |
| EP0113581B2 (en) | 1996-08-07 |
| DK3184D0 (en) | 1984-01-04 |
| JPS59136391A (en) | 1984-08-04 |
| JPH05186782A (en) | 1993-07-27 |
| GB8300016D0 (en) | 1983-02-09 |
| KR910004942B1 (en) | 1991-07-18 |
| AU2305183A (en) | 1984-07-05 |
| FI834887A0 (en) | 1983-12-30 |
| EP0113581A1 (en) | 1984-07-18 |
| JP2534818B2 (en) | 1996-09-18 |
| DK164792B (en) | 1992-08-17 |
| NO172650B (en) | 1993-05-10 |
| DD226901A5 (en) | 1985-09-04 |
| ATE80651T1 (en) | 1992-10-15 |
| DE3382624D1 (en) | 1992-10-22 |
| DE3382624T2 (en) | 1993-01-07 |
| DE3382624T3 (en) | 1997-01-02 |
| DK3184A (en) | 1984-07-05 |
| JPH0330637B2 (en) | 1991-05-01 |
| NO172650C (en) | 1993-08-18 |
| DK164792C (en) | 1993-01-04 |
| FI834887A (en) | 1984-07-05 |
| DD236940A5 (en) | 1986-06-25 |
| KR840007434A (en) | 1984-12-07 |
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