JPS6284185A - Intermediate distillate composition improved in low temperature flowability - Google Patents

Abstract

The cold flow properties of distillate petroleum fuel are improved by adding a polymer or copolymer containing at least 25 wt.% of an n-alkyl ester of the general formula <CHEM> wherein R1 and R2 are hydrogen or a C1 alkyl group, e.g, methyl, R4 is COOR3, hydrogen or a C1 to C4 alkyl group preferably COOR3 and R3 has an average number of carbon atoms from 12 to 20 and contains a methyl branch at the 1 and/or 2 position.

Description

DETAILED DESCRIPTION OF THE INVENTION Mineral oils containing paraffin wax are characterized by a decrease in fluidity as the temperature of the oil decreases. This loss of fluidity is due to the wax crystallizing into platelets and eventually forming spongy masses that trap the oil therein.

It has long been known that various additives act as wax crystal modifiers when mixed with waxy mineral oils. These compositions control the size and shape of the wax crystals and reduce the adhesion forces between the crystals and between the wax and the oil in such a way that the oil remains fluid at low temperatures.

A variety of pour point depressants have been described in the literature, and some of these are in commercial use.

For example, U.S. Pat. No. 3,048,479 discloses the use of copolymers of ethylene and C,-C, vinyl esters, e.g. evaporated vinyl acetate, as fuels, specialty heating oils, diesel fuels, jet fuels. ing. Hydrocarbon polymer pour point depressants based on ethylene and higher alpha olefins such as propylene are also known. U.S. Pat. No. 3,961,916 discloses the use of a mixture of copolymers, one a wax crystal nucleating agent and the other a growth inhibitor, to control wax crystal size.

GB 1.263.152 suggests that the size of the wax crystals can be adjusted by using copolymers with a lower degree of side chain branching.

For example, in British Patent No. 1.469.016, a copolymer of di-n-alkyl fumarate and vinyl acetate, which has traditionally been used as a pour point depressant for lubricating oils, is disclosed as having a high final boiling point. It has also been proposed that it can be used as a co-additive with ethylene/vinyl acetate copolymers in the processing of distillate fuels to improve the cold flow properties of the output fuel. According to British Patent No. 1.469.016:
These polymers are C4-Ca dicarboxylic acid Cs
C1e alkyl esters, especially lauryl fumarate and lauryl-hexadecyl fumarate. According to the Convention, the materials used are esters (polymer A) having an average of about 12 carbon atoms. It is noteworthy that these additives have been shown to be ineffective in lower end point "normal" fuels (Fuels 1 and 2).

As distillate fuels become more diverse, they either cannot be processed with existing additives or can be filtered at low temperatures to achieve the pour point reduction and wax crystal size control necessary to make them commercially viable. As a result, types of fuels have emerged that require uneconomically high concentrations of additives. One particular group of fuels that exhibit such problems are fuels that have relatively narrow and/or low boiling point ranges. Another type of fuel that is difficult to process is a fuel with a high end point;
Yet another type of fuel is the high wax content fuel typically produced in the Far East. A fuel is often characterized by its initial boiling point, final boiling point, and intermediate temperature at which a certain volume percent of the initial fuel distills off. Its 20-90% distillation point differs within the range of 70-100℃ and/or
A fuel whose 90% boiling point is 10-25°C of the final boiling point and/or whose final boiling point is 340-370°C is:
Generally considered narrow-boiling point fuels, they can be particularly difficult to process, sometimes being poorly affected by additives or requiring very high concentrations of additives. 3
Fuels with end boiling points above 70°C are sometimes known as high boiling point fuels and are also difficult to process. All distillations mentioned herein are according to ASTM D86.

As the price of crude oil increases, it is also important for refiners to increase their production and optimize their operations using rectification, also known as sharp rectification, which is also difficult to process with normal additives. Processing concentrations that are difficult or economically unacceptably high result in the required distillate fuel. Typical sharply rectified distillate fuels also have a 90%-end boiling point range of 10-25°C, with a typical 20-90% distillate range below 100°C, typically 50-
The temperature is 100°C. Both types of fuel have end boiling points above 340°C, generally 340°C - 370°C1, especially 34°C.
It has an end boiling point in the range 0-365°C.

Additionally, it is sometimes required to lower the temperature known as the cloud point of distillate fuels. The cloud point is the temperature at which wax begins to crystallize when the fuel is cooled. This requirement is applicable to the entire range of difficult-to-process fuels mentioned above and distillate fuels that typically boil in the 120-500°C range.

Copolymers of ethylene and vinyl acetate, which have previously been widely used to improve the flow properties of widely commercially available distillate fuels, have been found to be useful in the treatment of narrow-boiling and/or sharply rectified fuels. Known to be ineffective. Furthermore, the mixture described in GB 1.469,016 was also found to be ineffective.

Applicants' European Patent Application No. 85301047.
No. 8, No. 85301048.7, No. 85301675
．． No. 6, No. 85301676.4, Applicants disclose that copolymers containing very special alkyl groups, such as special fumaric ln-alkyl/vinyl acetate copolymers, reduce the pour point of the above-mentioned difficult-to-process fuels. and British Patent No. 1
．． No. 469,016's additives are claimed to be effective both in controlling wax crystal size for filterability including low end point fuels.

Applicants claim in these applications that these copolymers are effective in lowering the cloud point of many fuels across the entire range of distillate fuels.

We now demonstrate that the presence of a methyl branch in the 1- or 2-position of the alkyl group on the alkyl chain makes their addition It has been discovered that it can have economic and performance advantages without compromising its performance as an agent.

Accordingly, the present invention provides a method for improving the fluidity of distillate petroleum fuel oils having a boiling point in the range of 120-500°C using the general formula [1. R1 and R2 are hydrogen or a CI alkyl group, such as methyl, and R4 is C00R3, hydrogen or a C1-C4 alkyl group, preferably coORs
and R5 has an average number of carbon atoms of 12 to 20 and contains a methyl branch in the 1st and/or 2nd position. Use of additives in which the polymer or copolymer contains not more than 10% by weight of ester monomers containing alkyl groups containing more than 20 carbon atoms and preferably not more than 20% by weight of ester monomers containing alkyl groups containing less than 12 carbon atoms. I will provide a.

The composition of R1 can vary within the polymer structure and
Some of the 1 groups can be n-alkyl, but 1
No more than 10% by weight should contain more than methyl groups in the and/or 2-positions. The additives of the present invention preferably contain 0.0% by weight of distillate petroleum fuel oil.
0001-0.5% by weight, and the present invention also includes such treated distillate fuels.

The copolymer can be a copolymer of di-n-alkyl esters of dicarboxylic acids and can also contain 25-70% by weight of vinyl esters or alkyl acrylates or alkyl methacrylates or alpha olefins.

The polymers used in the invention are preferably used in paper pressure osmometry (Vapor Pr), for example.
1000-100.000, preferably i, o o
.

It has a number average molecular weight in the range of -30, OQO.

The esters used in the preparation of the copolymers can be prepared by esterifying the particular mono- or di-carboxylic acid with the appropriate alcohol or alcohol mixture. Examples of other unsaturated esters are alkyl acrylates and alkyl methacrylates.

The dicarboxylic acid mono- and di-ester monomers can be copolymerized with various amounts of other unsaturated esters or olefins, for example 5-70 mole percent. Such other esters may have the formula; or an unbranched C, -C, alkyl group), and R'' is R#
or hydrogen] are included. Examples of these short chain esters are vinyl esters such as methacrylates, acrylates, fumarates, maleates, preferably vinyl acetate and vinyl propionate. More specific examples include methyl methacrylate, isopropenyl acetate, butyl acrylate, isobutyl acrylate.

One preferred copolymer contains 40-60 mole percent dialkyl fumarate and 60-40 mole percent vinyl acetate.

Preferred ester polymers include -S the ester monomer in solution in a hydrocarbon solvent such as heptane or benzene or cyclohexane or white oil.
A nitrogen or carbon dioxide gas is used to eliminate oxygen, generally at a temperature in the range of 20-150°C and usually promoted with a peroxide or azo-type catalyst such as benzoyl peroxide or azocytate. It is produced by polymerization under an atmosphere of active gas.

Although the additives of the present invention can be used independently to impart a range of improvements to the cold flow behavior of distillate fuels, they are generally compatible with other additives known to improve the cold flow properties of distillate fuels. It is particularly effective when used in combination with agents.

The additives of the present invention are polyoxyalkylene esters, ethers, esters/ethers and mixtures thereof, especially those containing at least one, preferably at least two C3°-03° straight saturated alkyl groups and a molecular weight of 100-5 ,0
00, preferably 200-5,000 polyoxyalkylene glycol groups, and the alkyl groups in the polyoxyalkylene glycols contain 1-4 carbon atoms; It is particularly effective when used with mixtures of These substances have no European patent applications.
061895 forms the subject of issue A2.

Preferred esters or ethers or esters/ethers useful in the present invention can be represented structurally by the formula: %Formula %. In the above formula, R and R1 are the same or different, preferably (i) n-
alkyl, the alkyl group is straight chain and saturated, and 10-3
0 carbon atoms, A represents a polyoxyalkylene segment of a glycol in which the alkylene group has 1-4 carbon atoms, such as a polyoxymethylene or polyoxyethylene or polyoxytrimethylene moiety;
It is preferred that the glycol should be substantially linear, although some branching by lower alkyl side chains (as in polyoxypropylene glycol) can be tolerated. .

Suitable glycols are substantially linear polyethylene glycols (PEG) and polypropylene glycols (PPG) having a molecular weight of about 100-5.000, preferably about 200-2.000. Esters are preferred; fatty acids containing 10-30 carbon atoms are useful for reaction with glycols to form ester additives, and it is preferred to use CtS-CZ4 fatty acids, especially behenic acid. Esters can also be produced by esterifying polyethoxylated fatty acids or polyethoxylated alcohols.

Polyoxyalkylene diesters, diethers, ether/esters and mixtures thereof are suitable as additives, diesters being preferred for use as additives for narrow-boiling fractions, small amounts of monoethers and monoesters may also be present. Although possible and often produced during the manufacturing process, it is important for additive performance that a predominant amount of dialkyl compound is present. Particularly preferred are stearic acid diesters or behenic acid diesters of polyethylene glycol or polypropylene glycol or polyethylene/polypropylene glycol mixtures.

The additives of the present invention can also be used with ethylenically unsaturated ester copolymer flow modifiers.

Unsaturated monomers that can be copolymerized with ethylene include the general formula: [In the above general formula, R4 is hydrogen or methyl, and RS
is -00C:R, (where R8 is hydrogen or CI-Cz
@, more usually ct C1? , preferably Cl-C
or R3 is a -GOOR, group (where R1 is as above but not hydrogen) and R1 is hydrogen or as defined above unsaturated mono- and di-esters of 100 ORe.

Monomers when R3 and R7 are hydrogen and R1 is 100 CRs include vinyl alcohol esters of CI C1g, more usually NiCr C1g monocarboxylic acids. Examples of vinyl esters that can be copolymerized with ethylene include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, with vinyl acetate being preferred. The inventors have determined that the copolymer is 20
-40% by weight vinyl ester, more preferably 25-
Preferably it contains 35% by weight vinyl ester. The copolymer may be a mixture of two copolymers as described in US Pat. No. 3,961,916.

These polymers have been tested by vapor phase osmometry (vaporp).
has a number average molecular weight of 1000-6000, preferably 1000-6000, as measured by
Preferably, it is 3000.

The additives of the present invention can also be used in distillate fuels in combination with ionic or nonionic polar compounds capable of acting as wax crystal growth inhibitors in the fuel.

Polar nitrogen-containing compounds have been found to be particularly effective when used in combination with glycol esters or ethers or esters/ethers. Such ternary mixtures are within the scope of this invention. These polar compounds are preferably combined with an amine salt and/or at least one molar proportion of a hydrocarbyl-substituted amine and one molar proportion of a hydrocarbyl acid having 1-4 carboxylic acid groups or its anhydride. is an amide produced by the reaction of generally containing 30-300 carbon atoms in total, preferably 50
Esters/amides containing 50 carbon atoms can also be used. These nitrogen compounds are described in U.S. Pat.
), No. 534.

Suitable amines are usually long-chain C1t C4° primary or secondary or tertiary or quaternary amines or mixtures thereof, but shorter-chain amines are also used, since the resulting nitrogen compounds are oil-soluble and therefore Usually containing about 30-300 total carbon atoms can be used. The nitrogen compound preferably has at least one straight chain Ca. , preferably a C140za alkyl segment.

Suitable amines include primary or secondary or tertiary or quaternary amines, preferably tertiary amines.

Tertiary and quaternary amines can only form amine salts. Examples of amines include tetradecyl amine, cocoa amine, hydrogenated tallow amine, and the like. Examples of tertiary amines include dioctatecylamine, methyl-behenylamine, and the like. Amine mixtures are also suitable, and many amines derived from natural products are mixtures. Preferred amines have the formula HN Rt Rt (where R, and R2
is an alkyl group derived from hydrogenated beef tallow, and is approximately 4%
It is a secondary hydrogenated tallow amine consisting of C14, 31% G, and 59% CI8.

Examples of suitable carboxylic acids (and their anhydrides) for producing these nitrogen compounds include cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, cyclopencunedicarboxylic acid, sialfanaphthyl acetic acid, naphthalene dicarboxylic acid, and the like. . Generally, these acids have about 5-13 carbon atoms in the cyclic portion.

Preferred acids useful in this invention are benzenedicarboxylic acids such as phthalic acid, ortho-phthalic acid, and tere-phthalic acid. Particularly preferred is ortho-phthalic acid or its anhydride. A particularly preferred amine compound is an amide-amine salt produced by the reaction of 1 mole part of phthalic anhydride with 2 mole parts of di-hydrogenated tallow amine. Another preferred compound is a diamine produced by dehydrating this amide-amine salt.

The relative proportions of the additives used in the mixture are 1 part of the other additive(s) to 0.0 parts of the polymer of the invention containing n-alkyl groups containing an average of 12-18 carbon atoms. 5-20 parts by weight, more preferably 1.5-9 parts by weight of the polymer of the invention.

The additive system of the present invention can be used with any type of distillate petroleum with a boiling point in the range 120°C-500°C. R3
The preferred average number of carbon atoms in the group depends on the type of fuel being treated. For example, we found that polymers and copolymers in which the backbone (i.e., linear segment) of R3 contains 12-14 carbon atoms (i.e., R1 itself contains 13-15 carbon atoms) have so-called narrow boiling points. It is especially effective during minutes, but R3's bank bones average 13
-16 carbon atoms (i.e. R1 itself is 14-
Polymers and copolymers containing 17 carbon atoms have been found to be more effective in treating high end point fuels. The optimum value for R5 also depends on whether the polymer is used as the sole additive or mixed with other additives. The inventors have determined that R8 is suitable for distillate fuels.
We have also discovered that, although should generally be in the range of 12-18 carbon atoms, it is preferred that the compounds chosen to treat the particular fuel contain a high proportion of alkyl groups having an average number of carbon atoms. . For example, CIl! cta
If a polymer with a backbone is to be used, it is preferred that the content of monomers in which the backbone of R1 contains more than 14 carbon atoms is not more than 10% by weight; If ester monomers are to be used, it is preferred that not more than 10% by weight of the ester monomers used contain R1 groups with punk bones having less than 14 carbon atoms.

The additive system of the present invention may conveniently be supplied as a concentrate for addition into bulk distillate fuels. These concentrates can also contain other additives if desired. These concentrates preferably contain 3-75% by weight
, more preferably 3-60 %, most preferably 10
- Contains 50% of additives in the form of an oil solution. Also such concentrates.

Within the scope of the present invention.

The present invention is illustrated in the following examples in the “Journal of the
Institut op Petroleum (Journ)
Al of the In5titude of Pe
Additive Low Temperature Filter Clogging Point Test (Co) conducted by the method described in detail in tro, 1eum) Volume 52, Magnetic 510. June 1966, pages 173-185.
ld Filter Plugging Port
The effectiveness of the additive of the present invention as a filterability improver in oil response to Te5t (CFPP) is illustrated by comparison with other similar additives. This test is designed to correlate the cold flow properties of middle distillates in autodiesel.

Briefly, 4 Qml of the test oil sample is cooled in a bath maintained at about -34°C to provide a non-linear cooling of about -34°C/min. Periodically (starting at least 2°C above the cloud point and increasing the temperature by 1°C)
The ability of the cooled test oil to pass through a fine sieve in a predetermined period of time is tested using a test apparatus, which is a pipette with an overturned funnel at its lower end, placed below the surface of the test oil.

Strain a 350 mesh sieve with an area defined by a 12fi diameter across the mouth of the funnel. Each periodic test is started by applying a vacuum to the top of the pipette, allowing the oil to pass through the sieve and into the pipette at 20 mf.
It will be sucked up to the marked line indicating. After each successful passage of oil, immediately return the oil to the CFPP pipe. This test is repeated every time the temperature decreases by 1@ until oil no longer fills the pipette within 60 seconds. This temperature is reported as the CFPP temperature. The difference between the CPPP of fuel without additives and the CPPP of the same fuel with additives is the CFPP due to the additive.
reported as a decrease. A more effective flow improver will give a greater CFPP reduction at the same additive concentration.

The fuel used in these examples was ASTM-D-86 distilled, °C.
It was 68 398.

The additives used were as follows.

Plate preparation: 1:1 of di-CI & alkyl fumarate and vinyl acetate obtained by reaction of 2-hexadecanol and fumaric acid in cyclohexane using azodiisobutyronitrile as a catalyst at 80°C. A copolymer produced by solution polymerization of a mole stopper.

Commercial Acolu de Panol 45 containing primary n-C,4 and cps but with a small amount of 2-methyl congener and for comparison a C14 alcohol, n-C
, , and n C1 & alcohol mixture, n C1 &
Similar copolymers obtained from C1 & alcohols and alkyl fumarates.

The additive has a number average molecular weight of 2500 and contains vinyl acetate.
61) Oil containing 63% by weight of a polymer combination consisting of 3 parts by weight of a 1% ethylene/vinyl acetate copolymer and 1 part by weight of a copolymer of ethylene and vinyl acetate with a number average molecular weight of 3500 and a vinyl acetate content of about 17% by weight. It was tested in a 4:1 ratio with additive n, which is a solution.

The results obtained are shown in the table below.

n-C141721 Dopanol 45 19 21)
MeC+s 16 20 mixed n-Ct47+a 17 19n-
Ct6 12 13 CFP when using the above mixture of ethylene vinyl acetate copolymers
The decrease in P temperature was.

To further illustrate the present invention, various blends of fumaric acid isoC0°/vinyl acetate copolymers and fumaric acid normal CI4/vinyl acetate copolymers were prepared and pretreated with CF
It was evaluated in the fuel used in the PP test, and the results shown in the table below were obtained.

Claims (3)

[Claims] (1) An additive for improving the fluidity properties of distillate petroleum fuel oil with a boiling point in the range of 120℃-500℃, with the general formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the above general formula] , R_1 and R_2 are hydrogen or C_
1 alkyl group, e.g. methyl, and R_4 is COOR
n- of _3, hydrogen or C_1-C_4 alkyl group, preferably COOR_3, R_3 has an average number of carbon atoms of 12-20 and contains a methyl branch in the 1st and/or 2nd position] a polymer or copolymer containing at least 25% by weight of an alkyl ester, said ester polymer or copolymer containing not more than 10% by weight of an ester monomer containing alkyl groups containing more than 20 carbon atoms, and preferably containing 12 alkyl groups. Additives containing up to 20% by weight of ester monomers containing less than 20% by weight of carbon atoms. (2) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the above general formula, R_1 and R_2 are hydrogen or C_
1 alkyl group, e.g. methyl, and R_4 is COOR
n- of _3, hydrogen or C_1-C_4 alkyl group, preferably COOR_3, R_3 has an average number of carbon atoms of 12-20 and contains a methyl branch in the 1st and/or 2nd position] a polymer or copolymer containing at least 25% by weight of an alkyl ester, said ester polymer or copolymer containing not more than 10% by weight of an ester monomer containing alkyl groups containing more than 20 carbon atoms, and preferably containing 12 alkyl groups. 120°C containing 0.0001-0.5% by weight of additives containing up to 20% by weight of ester monomers containing less than 20% carbon atoms.
Distillate petroleum fuel oil with a boiling point in the range -500°C. (3) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the above general formula, R_1 and R_2 are hydrogen or C_
1 alkyl group, e.g. methyl, and R_4 is COOR
n-alkyl ester of _3, hydrogen or a C_1-C_4 alkyl group, preferably COOR_3, R_3 having an average of 12-20 carbon atoms and containing a methyl branch in the 1st and/or 2nd position and the ester polymer or copolymer contains not more than 10% by weight of an ester monomer containing an alkyl group containing more than 20 carbon atoms. and preferably contains up to 20% by weight of ester monomers whose alkyl groups contain less than 12 carbon atoms.